The Energy Show

Brad Heavner with CALSEIA Talks About Net Metering by Barry Cinnamon

Ed Murray Talks About Commercial Solar Hot Water Systems by Barry Cinnamon

Easy Home Energy Audits by Barry Cinnamon

Rooftop solar panels only work when they are in direct sunlight. So if you have a partially shaded roof, the output of your system will be lower than if there were no shading. And if your roof is heavily shaded, then rooftop solar is probably not going to be cost effective.

The reduction in output that shading causes depends on the type of shading, the orientation of your roof, and the use of microinverters or optimizers (these module electronics can help reduce shading problems). The most common examples of rooftop shading include trees, chimneys, neighboring structures, and utility poles. A small amount of shading -- perhaps from a vent pipe or utility pole -- will not have much impact on overall system output. But trees or other structures can have a big impact. A good rule of thumb is the object creating shading should be twice as far away as it is higher than the panels.

There is a home around the corner from me with a solar system on the west roof, and a big Magnolia tree right next to the house shading all the panels in the afternoon (when the sun should be shining directly on the panels). These west-facing panels are illuminated by the sun in the morning, but at a very oblique angle (about 20 degrees). Because of the shading, the panels never get direct sunlight perpendicular to the panels; the 20 degree sun angle means that these panels are generating only about 34% of what they could generate if there were no shading.

I hope the solar company that installed this system gave the homeowner an accurate estimate of the output (or lack thereof) of these shaded panels. Otherwise this homeowner will be unhappy when they get their annual utility true up statement and realize that their savings were not what they were led to believe.

Installing solar on a partially shaded roof is really an economic question. Will the resulting payback from the system -- after factoring in lower energy output from shaded panels -- still be acceptable? It might make sense to install panels in a partially shaded location if the installation costs for these incremental panels are low and the electric rates are high. Please Listen Up to this week’s Energy Show on Cinnamon Solar's Website for practical, economic advice for homeowners who are thinking about solar on a partially shaded roof.

Fires in homes are generally caused by kitchen mishaps, heating system fires or electrical malfunctions. When it comes to fire safety, the solar industry's track record is excellent -- with only a few documented cases in which the solar system actually caused a fire (generally due to improper wiring or equipment malfunctions).

Unfortunately, when home fires do occur, rooftop solar panels can become an impediment to a firefighter's ability to safely and quickly put out the fire. Firefighters must turn off the power to the rooftop system so that the panels are no longer energized; this is not always possible with high-voltage DC systems. In many cases, firefighters vent the roof so that smoke can escape and they can pour water on the source of the fire. With solar panels covering the roof, firefighter's ability to vent the roof over the fire is limited.

Improving fire safety as it relates to rooftop solar systems is being approached from two directions. First, new solar panel, racking and inverter standards are going into effect that will make solar equipment even safer. Second, new fire and building codes are being implemented that improve firefighter access to rooftops with solar. Unfortunately, these new standards are complicated and make equipment more expensive; and new firefighter access requirements significantly reduce available roof space for solar panels. It's an issue that requires a compromise among firefighter safety, property damage and clean energy generation.

My guest on this week's show is Matt Paiss, San Jose Fire Captain and Line Training Officer. Matt provides safety training for firefighters, particularly as it relates to rooftop solar power systems. He's also very involved in the development of new UL standards and local fire safety codes. So please tune into this week’s Solar Energy Show for a firefighter's perspective on the challenges and benefits of rooftop solar power systems.

Here’s a nightmare for you: at night, when you’re asleep and you think things are quiet, there are vampires sucking power out of your house and increasing your electric bill. The fact of the matter is that every plugged in electrical device in your home uses a small amount of standby power -- even if you think these devices are off.

When I explored each room of my house with a wattmeter, here is what I found:

· Computer devices used 66 watts: printer, cable modem, multiple wireless routers, laptop charger, mini-speaker

· Communications used 16 watts: iphone charges in several rooms, cordless phone

· Entertainment systems used 57 watts: flat screen TV, cable box, sound system, DVD player, subwoofer

· Kitchen appliances used 6 watts: microwave, coffee maker, dishwasher

· Other culprits used 23 watts: cordless vacuum, clock radio (remember those?), irrigation controls, garage door opener, furnace, thermostat transformer, doorbell transformer

These devices added up to 168 watts of 24x7 power. At my incremental electric rate of $0.25/kwh, these vampires sucked $368 out of my wallet last year. It is even worse if you have lighting controls, security cameras, extra fridges, wine coolers and IP thermostats. We have some solar customers who have over 500 watts of vampire devices – which in their top rate tier tacks on an extra $1,500 to their electric bill every year.

Please Listen Up to this week’s Solar Energy Show for ways to reduce your standby energy consumption without compromising your 21st century lifestyle.

Technologies, companies and business models in the solar industry come and go. But even in the relatively new solar industry, history repeats itself. Disappearing tax credits and incentives, financing scams, unreliable technology, societal doom (Y2k) and gloom (nuclear winter) -- it’s all happened before. We can learn a lot about building a sustainable solar businesses by talking to the solar contractors who have witnessed several of these boom and bust cycles over the past 20+ years.

My guest on this week’s Energy Show on Renewable Energy World is Pat Redgate, CEO of Ameco Solar. Pat has been installing solar thermal and solar PV systems at Ameco since 1974. Having successfully ridden the “solar coaster” for 40+ years, he has some terrific advice for solar customers (both residential and commercial) and solar installers who want to get into the business for the long term.

Please join me as Pat talks about the first wave of solar in the 70s and 80s, what happened when the tax credits disappeared, how he selects equipment to install for his customers, and his suggestions for running a successful local solar thermal and PV business.

According to Doc Brown, Marty McFly’s DeLorean needed 1.21 gigawatts to travel back in time. To put this in perspective, new gas power plants are about 0.5 gigawatts, typical large utility scale solar power plants are 0.1 gigawatts, and the average rooftop solar system is 0.000005 gigawatts (5,000 watts). Although it takes a lot of solar panels to generate the power our society needs, solar is now one of the cheapest and cleanest sources. And “clean and cheap” is now the world’s preferred power source: in 2013 the world added 143 gigawatts of new renewable energy generating capacity compared to 141 in new plants that burn coal, natural gas, or oil.

Fossil fueled power plants have not just taken a temporary back seat to renewables - we are witnessing a long term transition in the world’s energy sources. The price of wind and solar power is on par or less than fossil fuel electricity. Renewable energy prices are on a steady pace to get cheaper, while gas and oil will inevitably go up as supplies are constrained and climate change effects are considered. Coal plants are being decommissioned, and new nuclear plants are effectively doomed -- it took 36 years from start to finish for the last nuclear plant to come on line. Compare that to 45 days for a new solar power plant on your home’s roof, or three years for a utility-scale solar project.

Utilities are installing solar power plants to generate electricity for their customers because solar is cheaper. But this change in our energy sources will take many years, just as the complete transition from “horse and buggy” transportation to gas-powered cars took 50 years. As with other large-scale technological changes, customer economics will force the current incumbent energy providers to change (unlikely), or go out of business (more likely). It’s a virtuous cycle as more customers are satisfied with renewable power generation, and more people are employed in these industries. For more on this inexorable, economics-driven transition to a clean energy economy.

I’ve spent a lot of time over the past 15 years talking to homeowners about rooftop solar. More kitchen table chats and walks around the house than I can count. Some of the basic questions I hear again and again. Because they are new to solar, some of the most important questions do not even occur to homeowners.

On this week’s Energy Show we’re going to address some of the more obscure questions that homeowners should ask... and installers should be prepared to answer:

Why do I need a building permit for solar?

What happens if I run my electric meter backwards and don’t tell my utility?

Can I use the power from my solar system during a blackout?

Who covers the warranty on my solar installation and solar equipment?

Is 3% or 4% or 5% a reasonable projection for electric rate escalation?

If I sell my house, how will the new buyer value my solar installation?

Will that tree to the south of my roof shade the system and reduce its output?

Do I need to clean my solar panels?

Is there a catch with a “no money down” deal?

How much will I save with my solar system?

I had a little roof leak last year? Is it OK to put solar panels on my roof?

We’re talking about religion this week. Did I get your attention? How about if we talk about climate change, more renewable energy, dirty fossil fuels and solar subsidies? OK, we’ve already covered these topics. But now the Pope has chimed in with his “On Care For Our Common Home” Encyclical. I’m probably the worst person to comment (I got kicked out of Hebrew School). But I did read all 180+ pages of his Encyclical. There is no doubt in my mind that the Pope’s analysis and commentary will definitely affect U.S. politics related to clean energy.

First, the Pope describes the problem succinctly: pollution and climate change. Some quotes:

“Very solid scientific consensus indicates that we are presently witnessing a disturbing warming of the climatic system."

“Problem is aggravated by a model of development based on the intensive use of fossil fuels."

“Urgent need to develop policies so that, in the next few years, the emission of carbon dioxide and other highly polluting gases can be drastically reduced, for example, substituting for fossil fuels and developing sources of renewable energy."

“Economic interests easily end up trumping the common good and manipulating information so that their own plans will not be affected (greenwashing)."

"Whereas any genuine attempt by groups within society to introduce change is viewed as a nuisance based on romantic illusions or an obstacle to be circumvented (those pesky Climate Change nuts)."

He then continues with solutions that are both practical and grounded in economics:

"We know that technology based on the use of highly polluting fossil fuels – especially coal, but also oil and, to a lesser degree, gas – needs to be progressively replaced without delay."

"Until greater progress is made in developing widely accessible sources of renewable energy, it is legitimate to choose the lesser of two evils or to find short-term solutions (natural gas as a temporary bridge)."

"Taking advantage of abundant solar energy will require the establishment of mechanisms and subsidies … The costs of this would be low, compared to the risks of climate change (renewable energy incentives)."

So what does this all mean? Clean energy supporters and environmentalists are happy to have the Pope on their side. Dirty energy proponents and climate deniers have to argue against the formalized position of the Catholic church...I’m sure the Koch brothers aren’t happy. Right wing Catholic politicians have to choose between agreeing with the Pope -- or accepting fossil fuel campaign money.

Overall, this Encyclical — and subsequent Papal speeches — will gradually dissolve the political right-left gridlock on climate change and the actions necessary to mitigate it. I am particularly looking forward to the Pope’s address before Congress in September (ironically, the Pope was invited by Speaker of the House Boehner). So please Listen Up to this week’s Solar Energy Show for more details on the Pope’s Encyclical and its positive impact on the continued growth of renewable energy throughout the world.