The Energy Efficiency Podcast

LEED

Welcome to LEED: The Energy Efficiency Podcast – episode 13, the podcast that brings you a mix of energy efficiency news, products and tips all year round. We’re interested in profiling people and products involved in promoting energy efficiency habits, products and information, so please do get in touch if you have something to contribute.This week: LEED, another green building accreditation scheme. How does it differ from BREEAM? City bike hire – is it an environmental and health success? And energy efficiency in the music industry – is it hitting the right note?

Heating

Glasgow’s beautiful tenement homes

But before we get on with our advertised features, there have been a couple of articles recently about heating homes from local waste or untapped heat. A project in the east end of Glasgow is looking at the potential for heating homes with geothermal energy from untapped mine water. The project is expected to continue for 15 years. It’s funded by the Natural Environment Research Council (NERC) and the British Geological Survey (BGS) as part of the £31 million UK Geoenergy Observatories Project.

Across the UK about 9 million buildings, that’s a quarter of all UK homes and businesses, sit on former coalfields. Boreholes are being dug into flooded mine workings as part of the Glasgow project. They will be monitored to provide data on water movement, temperature and water chemistry as well as changes to the chemistry and physical and microbiological properties just below the surface.

The Coal Authority believes there is enough geothermal energy in coal mines to heat millions of homes. It’s creating a map of potential mine water resources. Systems like this are already in use in other countries, and the Glasgow project is intended to see how much more widely this form of heating could be used. It has potential as a heat store, something which has been a real challenge for renewable heat systems. A similar project is underway in Stoke, and there is even potential for extracting heat from the Clyde.

London Underground

In north London, a scheme is underway to pump heat from a ventilation shaft in the tube network to homes and businesses in Islington by the end of this year. The homes and businesses that will benefit from this scheme are part of a heating scheme in Islington. At the moment 800 or so homes are heated by the Bunhill Energy Centre, a combined heat and power plant which for seven years has provided heat to council houses, schools, a swimming pool and a leisure centre. It generates electricity, and uses the heat that is a by-product to supply hot water.

The new addition to the scheme uses heat that would otherwise be wasted. An additional 450 homes will benefit. In summer, the system will be reversed to introduce cool air into the tube tunnels. It’s hoped this model can be replicated across London. The GLA reckons heat currently wasted could meet nearly 40% of London’s heating requirements.

LEED

Last week we looked at BREEAM sustainable building accreditation. This week we cast our eye over LEED: Leadership in Energy and Environmental Design. One instant difference between the two is that where BREEAM was developed by a British organisation, the Buildings Research Establishment, LEED is an American development.

Other countries have their own systems too, such as Green Star in Australia and Assessment System for Built Environment Efficiency in Japan. Described by Wikipedia as “one of the most popular green building certification programs used worldwide”, LEED was developed by the US Green Building Council (USGBC).

Categories

Similarly to BREEAM, LEED is based on a ratings systems for design, construction, operation and maintenance of buildings aiming to be environmentally sound and efficient in use of resources. The main categories are Sustainable sites, Water Efficiency, Energy and Atmosphere, Materials and Resource, and Indoor Environmental Quality. In 20

BREEAM

Motorbike repair shop in The Gambia

Welcome to BREEAM: The Energy Efficiency Podcast – episode 12, the podcast that brings you a mix of energy efficiency news, products and tips all year round. We’re interested in profiling people and products involved in promoting energy efficiency habits, products and information, so please do get in touch if you have something to contribute.

This week: BREEAM – we often mention it, but what is it? The health benefits of energy efficiency, and mending household items – it’s new and cool but some of us have been doing it for years.

Circular economy

But before we get on with our advertised features, last week the Guardian reported on a business complex in Rotterdam housing 30 businesses. Nothing new in that you might think, but BlueCity brings all the businesses together to trial a circular economy. The principle of the circular economy is that nothing is wasted, ie that materials remain in use for as long as possible and use of new raw materials is minimised.

The Netherlands has in place a government-wide programme aimed at developing a circular economy in the Netherlands by 2050. If you so wish there’s a 72 page PDF on this, in English, that you can download from the Dutch government website – link in the show notes. The plan is to halve raw material use by 2030, and Rotterdam wants to be in the vanguard of this. Rotterdam is a port city which has led to it becoming an emissions hotspot and consumer of significant quantities of raw materials.

SMEs

Tropicana’s “giant greenhouse”

Interestingly, the Dutch government has identified SMEs as crucial to the success of the circular strategy programme. They make a big contribution to Rotterdam’s economy and so can lead in changing business habits. Rotterdam is conducting a four year pilot project, in which sites such as BlueCity will be central. The building is a disused Center Parcs venue named Tropicana. Businesses moving in represented a shift from circular economy planning to doing.

Renovation of the building isn’t complete but new parts are opening. In the basement worms compost all organic waste. Reuse of a derelict building sets BlueCity apart from other projects globally, although the Dutch do seem to have a flair for reusing old sites. BlueCity’s unique setting, in a redeveloped holiday centre, has attracted the sort of attention that means it can be 90% self-funded. However some involved fear that Blue City will become more of a tourist attraction than a catalyst for wider change. To counteract this Blue City is connecting entrepreneurs with corporates who want help with waste solutions. It runs events, including debates, to deliver practical advice.

The concerns about becoming a tourist attraction instead of a game changer are understandable, but at this stage we still seem to need colourful projects to bring home what can be achieved. Only when sustainability behaviour excites no attention whatsoever but is part of the furniture will we really have succeeded.

BREEAM

We’ve mentioned BREEAM a few times now in the context of buildings that have achieved high BREEAM ratings. Nothing to do with fish, BREEAM stands for Building Research Establishment Environmental Assessment Method. It’s a scientifically-based method developed by the Buildings Research Council (BRE) that assesses, rates and certifies the sustainability of buildings. It began in 1990 and in the last almost 30 years over half a million certificates have been issued in 83 countries.

BREEAM categories evaluate energy and water use, health and wellbeing, pollution, transport, materials, waste, ecology and management processes. A building can be rated Acceptable (In-use scheme only), Pass, Good, Very Good, Excellent and Outstanding. Crucially a good BREEAM rating provides market recognition of a building’s sustainability.

Expansion

BREEAM started out assessing new office buildings. This expand

Sheep’s Wool Insulation

Herdwicks in the Lake District

Welcome to Sheep’s Wool Insulation: The Energy Efficiency Podcast – episode 11, the podcast that brings you a mix of energy efficiency news, products and tips all year round. We’re interested in profiling people and products involved in promoting energy efficiency habits, products and information, so please do get in touch if you have something to contribute.

This week: grants for energy efficiency works – what’s available to help you make your home cosy for winter? Sheep’s wool insulation – the whys and wherefores, and energy efficiency in business – how to improve your offering while saving money.

Power failure

But before we get on with our advertised features, at the end of last week parts of the UK experienced a total power failure. As well as homes left without power, hospitals, airports, trains and traffic lights were affected.

The lights went out because two power stations failed within minutes of each other. One was a gas plant, the other a wind farm, which together produce 5% of our electricity. This was grist to the mill of those who oppose wind farms, but the problem was not, as has been reported by some outlets, that there was “too much wind” or indeed its opposite, not enough wind. The gas powered plant shut down in response to a technical issue. Automatic systems reduced power output significantly at the wind farm.

Part of the issue is that the National Grid is not prepared for power failure on this scale. However, safety systems operated as they should have. Power services to the vast majority of the country were maintained. These safety systems will come under review as part of an investigation into the causes of the blackout. Until it reports back there’s nothing to be gained by speculating on the causes of the blackout, although the National Grid has already ruled out a cyber attack.

Swift reconnection

The power outage had so much impact as it happened at rush hour on a Friday in August, but many of those affected were reconnected within 15 minutes. A power failure on this scale hasn’t happened in over a decade. The National Grid CEO pointed out that the UK has “statistically one of the most reliable energy networks not only in Europe but anywhere in the world.”.

He puts this down to massive investment from the energy industry in distribution and transmission networks over the last 30 years. Despite this, the National Grid could face a fine for a power outage on this scale.

Grants for energy efficiency works

We’ve mentioned grants a couple of times in past episodes, so we thought it was time to look at the detail. What can you, as a householder, access to improve the energy efficiency of your home? It depends on where you live and your circumstances. Many local authorities and groups run their own funding systems. Eligibility can depend on age, status as a homeowner, private tenant etc, and income.

Complex

Identifying precisely what any given household might be eligible for can be complex. For example, in Scotland loans of nearly £40,000 are available to owner-occupiers and private landlords for all sorts of improvement works including connection to a district heating network. Those struggling to pay for heating their home can access the Home Energy Efficiency Programmes for Scotland and the Warmer Homes Scotland Scheme. There’s support for tenants, and for people installing renewables. Choose.co.uk describes the system as complicated and suggests contacting the Energy Savings Trust’s partners to check eligibility.

Park homes

The Warm Home Discount scheme is run by the government. Strictly speaking it isn’t for home improvements, but is a discount on your electricity bill between September and March. If your electricity supplier also provides you with gas you can get a discount on your gas bill instead. The scheme ran last year and opens to new applicant

Hydropower

Niagara

Welcome to Hydropower: The Energy Efficiency Podcast – episode 10, the podcast that brings you a mix of energy efficiency news, products and tips all year round. We’re interested in profiling people and products involved in promoting energy efficiency habits, products and information, so please do get in touch if you have something to contribute.

This week: hydropower – is it really as green as it seems? Energy efficiency in tourism – how can we travel without harming the places we want to see? And starting our look at different types of insulation, we ask what is Kingspan?

But before we get on with our advertised features, this week website Solar Power Portal reported that the National Grid is using artificial intelligence (AI) to improve solar forecasting by a third. Poor forecasting can result in power system instability and higher operating costs. In some countries, for instance Australia, power generators are penalised for providing inaccurate forecasts. Improved forecasts help the National Grid and similar organisations worldwide run their systems more efficiently and economically. As renewables form an increasing chunk of our energy mix, this facility becomes ever more important.

The National Grid is working with the Alan Turning Institute on this project. Named after the pioneering mathematician, computer scientist, philosopher and Bletchley Park code-breaker, the Alan Turning Institute conducts research into AI. The project is funded by the Ofgem Network Innovation Allowance.

In this case, AI helps by churning through many more variables than the National Grid has historically been able to do. The results are combined with other machine learning techniques to come up with a more accurate forecast. In Colorado, USA, an AI project focusses on wind power. The system draws information from satellite reports, weather stations and wind farms. Algorithms identify patterns from the data and make predictions based on them. The British project also includes wind data. Today though the AI won’t have to work very hard to forecast that as it’s cloudy and damp, solar is providing just 9% of our power.

Hydropower

The Three Gorges Dam, China

We had already planned to cover hydro power this week before Toddbrook reservoir at Whaley Bridge in Derbyshire began to show signs of strain. There are nearly 3000 dams in England, Wales and Scotland. They’re for drinking water, canal management and so on, but some are part of hydro-electric schemes. Worldwide, dams are commonly part of hydro-electric energy generation. The Three Gorges Dam in China is the largest in the world. While hydroelectric power is viewed as a low carbon means of economic development, building dams is controversial environmentally.

Environmental cost

Fish ladder at Pitlochry

As we looked at last week with wind power, there is an environmental cost to building hydroelectric power stations. Concrete is a big environmental bad boy. The only mitigating factor is that across the lifetime of a hydro plant the emissions will be offset by emissions-free electricity. At the moment the five largest power stations in the world are hydroelectric power station with dams.

Apart from the emissions associated with building dams, they interrupt the local ecology and emit greenhouse gases. Fish migration can be badly affected but this can be improved by fitting fish ladders. Research in America has led to the development of turbines that fill or injure far fewer fish. Dams affect local agriculture by diverting and storing water and affecting water chemistry and silt formation. A recent report described the human costs of large dams as “routinely underestimated”. Communities can be displaced when fishing and agriculture are affected, and land is taken for building dams and reservoirs.

Smaller plants

Water wheel

Recognising these negatives, the EU encourages the use of smaller hydro plants that don’t use dams and is funding

Wind Power

Wind farm

Welcome to Wind Power: The Energy Efficiency Podcast – episode 9, the podcast that brings you a mix of energy efficiency news, products and tips all year round. We’re interested in profiling people and products involved in promoting energy efficiency habits, products and information, so please do get in touch if you have something to contribute.

But before we get on with our advertised features, this week the Guardian reported that architects and engineers are calling for a ban on glass buildings. Glass buildings become extremely hot in the sun and use lots of energy to cool down. This carbon-emitting energy requirement makes no sense in a climate emergency.

In theory using glass to let in light and create heat is a good thing, but when it’s managed properly. Solar gain is an important element of passivhaus design, where it is understood and carefully managed to prevent occupants overheating. Many corporate and commercial glass buildings are designed just for looks. In these heat can build up to unbearable levels without heavy duty air conditioning. As we looked at in our feature on passive cooling, energy used to cool buildings has doubled in the last few years. Buildings can still benefit from solar gain in winter with smaller windows. Natural ventilation can make a huge difference but this can be the short straw in a polluted and noisy area.

Some steps are being taken. Mayor of New York Bill de Blasio has banned excessive use of glass and steel. This is a bit of a climbdown from the ban he spoke of originally. Sadiq Khan, mayor of London, has ruled out a ban. This is surprising given how forward-looking the London Plans have been on the benefits of green technologies (we looked at this last week in the green roofs feature). The new London Plan, coming into force next spring, requires an assessment to be made of a building’s lifetime energy use. It’s hard to see how a standard glass building would come out well of this assessment.

In the Guardian article Martin Fahey, head of sustainability at Mitsubishi Electric, referred to the importance of keeping air conditioning equipment in good working order. Maintenance of equipment has come up repeatedly in keeping energy efficiency at optimum. Fahey hopes that commercial customers will want to do the right thing if only for the sake of their image.

The Edge, Amsterdam

Some hi-tech glass can become opaque in hot weather. Others can generate electricity, such Deloitte’s Edge building in Amsterdam’s Zuidas business district. It uses intelligent design to cut its energy requirement by 70% on a similar building. On three sides it has smaller, opening windows, and one face is glass. It’s been awarded the world’s highest BREEAM rating (Building Research Establishment Environmental Assessment Method) This isn’t a magic bullet however as the specialist glass is nigh on impossible to recycle.

 

WIND POWER

It’s a rainy day today and demand on the grid is higher than I’ve seen it for a while. We’re using no coal or oil. Natural gas is providing almost half our power, via CCGT. Renewables are providing about 27% of our power and wind is contributing 10% of that. What is wind power?

As the NES website says, wind power ain’t new. It’s been pushing boats along and powering windmills for thousands of years. It’s magic, actually. Well, no it’s not but as the wind turns the blades which turn a shaft, a generator converts that kinetic energy into electrical energy. That’s where the magic happens. The electricity is then converted into the right voltage for the local network and exported to the grid. A gentle breeze is enough to turn the blades, but faster winds generate more electricity. If it gets too windy wind turbines will shut down to avoid suffering damage. From an individual wind turbine on a house to giant wind farms out at sea, the mechanics are the same. One standard on

Solar Power

A solar array in the USA

Welcome to Solar Power: The Energy Efficiency Podcast – episode 8, the podcast that brings you a mix of energy efficiency news, products and tips all year round. We’re interested in profiling people and products involved in promoting energy efficiency habits, products and information, so please do get in touch if you have something to contribute.

Before we get on with our advertised features, on Monday morning the Guardian reported on a scheme to generate domestic fuel from dirty plastic waste.

Dirty recycling

Items for recycling should be clean and contain nothing non-recyclable. This is why mixed materials are such an issue. Recyclable materials are wasted and go to landfill if they’re mixed up with non-recyclable materials in the same item. If recycling is dirty it can’t be used.

The worst culprit is food. That’s why silver foil is not usually recyclable. It’s infinitely reusable if it doesn’t get dirty as such, but the foil with bacon fat all over it has to go in the bin. If a householder knows this then contaminated waste won’t enter the recycling foodchain, but mistakes happen all the time. That’s distinct from aspirational recycling, when items go in the green bin in the hopes they can be recycled. Or perhaps the belief that they should. Even paper and glass can be contaminants if they go in the wrong bins. To quote Rubicon Global,

“Contaminants turn your recycling into nothing more than trash.”

This is an entire subject with global repurcussions and one we’ll return to at a later date.

Hydrogen

Help may now be at hand. Work at the University at Chester has been looking at how to use this dirty recycling to create fuel. Researchers have found a way to produce hydrogen. Hydrogen can fuel homes and cars without emitting greenhouse gases. Waste is burnt at 1000 degrees in a glass kiln. The waste instantly breaks down to release gases including hydrogen.

Two waste energy business have come together to develop this research commercially. Later this year production will begin at a plant at Ellesmere Port in Cheshire. Owner of the plant Peel Environmental reckons that a walloping 25 million tons of contaminated recycling will be kept out of landfill and the seas.

Why is hydrogen such a big deal? Hydrogen can take over tasks currently met by traditional gas. Hydrogen can be used for cooking, heating homes and hot water, and fuelling vehicles. It could play a huge part in the UK meeting its climate targets.

There is a downside however. The production of hydrogen emits powerful greenhouse gases including methane. Methane is a disaster, but the plant plans to trap it and use it to generate electricity. The Guardian article describes this process as no “more polluting than the UK’s existing gas-fired power plants”. That’s not a ringing endorsement, but it goes on to make the point that it means no more gas need be pulled from the ground. It highlights again the need for effective carbon capture technology.

OLYMPUS DIGITAL CAMERA

The technology has been developed in collaboration with Asian companies. Hydrogen fuel is already commonly used in Japan, as we looked at in episode 3. Increased production of hydrogen in Asia would make strides in reducing their dependence on coal burning plants. Ep 3 looked closely at fuel use and generation in Japan.

 

 

Solar Energy

Mid-morning on Monday 22nd July, renewables are providing 15% of the UK’s power requirements. Wind is producing about 2/3 of that, solar power most of the rest. It’s a bright sunny day in parts of the UK and it’s windy. We’re using no coal or oil just now. So would fitting PV panels to your home keep you in electricity all year round? Let’s look at the facts.

Photovoltaic cells – PV cells – work by turning sunlight into an electric field. More sunshine means more electricity but PV cells don’t need brigh

Ground Source Heat Pumps

Welcome to Ground Source Heat Pumps: The Energy Efficiency Podcast – episode 7, the podcast that brings you a mix of energy efficiency news, products and tips all year round. We’re interested in profiling people and products involved in promoting energy efficiency habits, products and information, so please do get in touch if you have something to contribute.

Before we get on with our advertised features, the Guardian reported last week on the progress made towards hitting net zero by various local authorities in England. This is on the back of Labour leader Jeremy Corbyn urging local authorities to take a lead on reducing carbon emissions.

Progress varies wildly across the UK. This will inevitably reflect variations in population density and affluence around the country.

Stroud in Gloucestershire

Since the 1990s Stroud in Gloucestershire has taken this bull by the horns. In 2015 it became the first local authority in Europe to become carbon neutral. As well as undertaking domestic energy efficient retrofits it has fitted solar panels to houses and all municipal buildings. Residents are feeling the difference and spending less on energy bills.

Collaboration

Its grade II listed council building has secondary glazing and internal insulation and sources all heat from renewables. Through collaboration with other local authorities Stroud has boosted recycling rates to 61%.

It has plans for more. It wants to become a carbon neutral area by 2030, 20 years ahead of the government’s target. It will do this by using electric vehicles, making all homes (that’s ALL homes) energy efficient, using low- to no-carbon electricity and heat generation and tree planting. It’s aiming to facilitate cycling, walking and renewable-powered public transport. At this rate Stroud will also become one of the healthiest local authorities in England.

Simon Pickering, a Green party councillor and chair of the council’s environment committee, makes the point:

“It will no longer be business as usual to cut the energy use of all buildings by at least 80%, generate over half the district’s electricity needs from renewable sources and transform how we travel.”

And this is the point, serious policy shift must be implemented by an authority wanting to see results.

However Stroud and other authorities including Nottingham and Oxford are the bold few. Despite widespread announcement of climate crisis among local authorities in the UK many take an illogical approach to carbon reduction. Manchester’s plans for carbon neutrality explicitly exclude emissions from aviation. In Norwich and Hereford there are road-building plans. In Hereford in particular these plans have been heavily criticised for not tackling the real cause of congestion – short city centre journeys that could be replaced by public transport or walking and cycling infrastructure. Going even further, Cumbria County Council has approved opening a new coal mine. This is another example of the postcode lottery at work in the UK.

Ground Source Heat Pumps

Heat pumps are used in about 100,000 homes in the UK. In Sweden, Germany, Switzerland and the USA they’ve been widely used for years.

Underfloor heating going in

Ground source heat pumps (and their near relations air and water source heat pumps) have become the heating method of choice for low-energy builds. This is for two main reasons. Firstly, although they need electricity to run, the heat the pumps draw in is continually and naturally renewed. Secondly, heat pumps work best in a house with levels of insulation and draught-proofing well above average. Due to its lower temperatures a heat pump system tends to work best with under-floor heating and warm air heating systems.

How it works

The temperature a couple of meters below ground stays at around 8-12 degrees all year round. A ground source heat pump extracts this heat through buried loops of pipe about 100m long. The pipe has a mix of w

Electric Heating

Welcome to Electric Heating: The Energy Efficiency Podcast – episode 6, the podcast that brings you a mix of energy efficiency news, products and tips all year round. We’re interested in profiling people and products involved in promoting energy efficiency habits, products and information, so please do get in touch if you have something to contribute.

Carbon capture machinery at a coal mine

Before we get on with our advertised features, we looked recently at the role of carbon capture in helping the UK achieve Theresa May’s net zero target. Carbon capture traps carbon as it’s produced, preventing it entering the atmosphere. The carbon can then be used to create chemicals required by industries including food (mm) and medicine. Last week, a division of the Indian-owned company Tata announced a new carbon capture project, the UK’s biggest, through a plant in Cheshire. It expects to prevent 40,000 tonnes of carbon entering the atmosphere each year, the equivalent of removing about 20,000 cars (what type of cars?) from the roads.

The plans are backed by the British government, which is contributing about a quarter of the £16m cost through a grant. An existing carbon capture trial at the Drax power plant in Yorkshire will receive a £5m boost, aimed at keeping 16m tonnes of carbon from the air by the mid-2020s. The government is helping to support nine carbon capture projects and supporting the development of a net zero industrial cluster in the UK by 2040.

The Tata project intends to use the removed carbon to create a high grade liquid carbon dioxide, used in creating baking soda. Sodium bicarbonate is used by pharmaceutical companies to make products including indigestion remedies and eye drops. Tata is the only company in the UK making sodium carbonate, which is used in detergent and glass manufacture. As Martin Ashcroft, head of Tata Chemicals Europe, points out, this carbon capture project helps Tata ensure a good supply of essential materials.

Tata is an enormous company with interests in many sectors. It owns one of India’s biggest energy companies, and has pledged to end investment in fossil fuel energy plants to focus on renewables instead. Realistically, it is behemoths such as Tata that have the influence and financial muscle to make changes the ordinary person can’t effect, so let’s hope that where Tata leads, on these issues at least, others will follow.

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Electric heating

Last week we looked at gas heating, concluding that although it is cheaper per unit than electric heating and emits less CO2 than almost any other form of heating, it’s expensive and disruptive to install, an inherently risky material and, of course, a fossil fuel. Much natural gas production comes from fracking, particularly in the USA, which is widely accepted to be an environmental disaster.

White electric radiator

In the UK, many houses that aren’t connected to the gas network instead use electric heating. About 4m households here don’t have access to gas, and of these about half use electric heating, so at two million households that’s a noticeable minority. Of these two million or so households, the vast majority use night storage heaters with the rest using plug-in fan heaters. A small minority of less than 100,000 households use heat pumps, which need electricity to run but are a whole subject in their own right and will be profiled next week.

Is it really more expensive?

Electric heating is more common in flats than houses, and homes using it tend to have a lower energy efficiency rating with the occupants on lower incomes, directly leading to fuel poverty. A report from Ofgem, Insights Paper on Households with Electric and Other Non-Gas heating, goes into deep but quite interesting detail on the demographics of electric heating customers, and how things will probably become worse for them financially over the next few years as tariffs and benefits become unba

Gas Heating

A Tesco supermarket

Welcome to Gas Heating: The Energy Efficiency Podcast – episode 5, the podcast that brings you a mix of energy efficiency news, products and tips all year round. We’re interested in profiling people and products involved in promoting energy efficiency habits, products and information, so please do get in touch if you have something to contribute.

This week: gas heating, where to start with draughtproofing your home, and energy efficiency in self build. Before we get on with our advertised features, the Guardian recently ran an article suggesting that supermarket fridges could form a nationwide virtual battery for the National Grid. Research in a mocked-up supermarket, undertaken by Tesco and the University of Lincoln, shows that electricity can be provided in short bursts to the grid by briefly stopping power to supermarket fridges. Power is already turned off to the fridges each day to allow for deforsting, and the proposed system would replicate this. The power wouldn’t be off long enough to affect the food, but the top-up power could help balance a dip in the grid’s energy supply.

The Guardian article quotes Professor Simon Pearson of the University of Lincoln:

Cold food is, in fact, the UK’s largest battery. There is sufficient ‘cold energy’ in the food to keep a refrigerator cold if the system reduces power for short periods to help offset power shortages on the National Grid.”

The National Grid already operates this type of system with companies that own utility-scale batteries. Increasing the scale of the operations to include a nationwide supermarket chain increases capacity while helping supermarkets reduce their carbon footprint. Commercial refriferation systems make up about 12% of the UK’s carbon emissions, with energy bills accounting for 1/3 of costs for a typical retailer. This is one example of technology helping the UK to reach its net zero target.

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Gas heating

An oil tanker delivering to a rural area

Last week we looked at district heating networks, concluding that they were more energy efficient than heating produced by individual boilers, and ideally produced their heat from renewable sources or waste heat. This week we look at mains gas heating. Wikipedia defines natural gas as “a non-renewable hydrocarbon”, describing it as “a major cause of climate change” both in itself if it leaks, and because of the CO2 emitted when it’s used.

Widely available

Gas heating is far more widely available than district heating, but it isn’t available everywhere. Rural areas tend to be less likely to be connected to the gas network, so oil is a more commonly used fuel in the countryside. OVO Energy states that 3.9million homes in the UK are without gas heating, and Citizen’s Advice Scotland quotes a figure of 46% of households in Wales without access to gas.

In the UK the average gas-connected home is built from the 1950s, and average off-gas home up to the 1930s. Of gas-connected homes, over 75% are within bands A-D of the Energy Performance Certificate rating, ie the best-performing four bands.

8 million gas boilers are sold in the UK every year. Simply, they heat up water to pump through pipes to radiators and provide hot water to kitchen and bathrooms. According to Rointe, suppliers of electric heating infrastructure, gas heating systems haven’t changed much over the years. They tend to be more expensive to install than electric systems, being more complex, and don’t last as long. Gas heating comes with the risk of carbon monoxide leaks and burst pipes, and is the UK’s biggest greenhouse gas emissions source.

Cheap to use

The Energy Saving Trust describes gas as usually being the cheapest form of heating fuel available, and having the lowest CO2 emissions apart from wood. OVO has pulled together data on energy prices and the energy efficiency of the most commonly used forms of fuel, and presented t

Net Zero

Welcome to Net Zero: The Energy Efficiency Podcast, episode 4, the podcast that brings you a mix of energy efficiency news, products and tips all year round. We’re interested in profiling people and products involved in promoting energy efficiency habits, products and information, so please do get in touch if you have something to contribute.

This week: net zero, tenants’ rights to energy efficiency works in their homes, and district heating. But before we get on with our advertised features, at the end of last week the UK press was reporting the National Grid’s prediction that zero carbon energy sources will provide more than half the UK’s energy in 2019.

Coal-fired power is declining, replaced by clean sources of power such as wind, solar, hydro and nuclear. So far this year coal-fired power has generated only 3% of power, whereas renewable eneergy has leapt from generating just 2% to 20%. This comes on the back of Britain’s longest stretch of coal-free power generation recently, equivalent, according to a Guardian article, to preventing 5m tonnes of CO2 being release into the atmosphere, the equivalent of a staggering 12bn miles driven in a car.

The government plans to phase out all coal-fired power generation in just six years from now, so the Natinal Grid has the job of ensuring other sources can replace it. It is spending over £1bn a year to adapt the grid for all renewables.

Net Zero

Carbon capture technology at a coal mine

Net zero is in the news every day just now it seems – so what is it? According to the LSE’s Grantham Institute on climate change and the environment, net zero refers to emissions produced and emissions removed from the atmosphere. This can be achieved by reducing the emissions, extracting carbon, or a bit of both. The Grantham Institute draws a distinction between net zero, and gross-zero:

“In contrast to a gross-zero target, which would reduce emissions from all sources uniformly to zero, a net-zero emissions target is more realistic because it allows for some residual emissions.”

Trees

There are many permutations of how to achieve net zero. Simple tree-planting can help as trees absorb carbon dioxide. A positive knock-on from this is increased habitat for creatures of all sorts and an enhanced landscape, but this is a slow process. An article from Left Foot Forward claims that tree planting alone could deal with a third of greenhouse gas reductions needed in the next decade. This is the subject of political pressure for increased funding and government attention. Encouragingly, the CCC recommended a huge programme of reforestation and peat moorland restoration in its recent report on net zero.

Carbon capture

Technology has a huge role to play, most prominently carbon capture and storage. This in theory permits the continued burning of fossil fuels. The carbon is compressed to a liquid state then pumped deep underground into now-empty coal mines, gas reservoirs and so on. This system can capture up to 90% of carbon released from burning fossil fuels in electricity generation and some industrial processes.

Direct Air Capture removes CO2 directly from the air, converting the oxygen and storing the carbon. This type of system is used in sealed environments such as submarines and space craft, but it’s difficult to make economical at scale. As usual, there is the need to make a business case for developing technologies, creating a market for so-called ‘negative emissions’. An article on Business Green suggests that this can be achieved through a government-run system or regulated market.

Offsetting

Emissions cannot be removed completely. The CCC estimates 130 million tonnes of carbon dioxide-equivalent will still be emitted even with current technologies maximised, mainly from industry, aviation and shipping, and agriculture. Offsetting seems to be the only way to deal with these, at the moment. The Grantham Institute explains th