Chris Troutner is an established electrical engineer. His specialties involve electrical testing and validation. In his spare time, he works with solar power and has become a leading expert in this rapidly developing field. His current side project is the Free Charge Controller Project http://www.freechargecontroller.org). Chris has been writing about the benefits of solar power to the general public since early 2011.
Chris, tell us when you first wanted to become an expert in solar power and why?
Alternative energy has always been a subject near and dear to my heart. I grew up in the country, with a large stretch of forest behind my house, where I spent most of my childhood. As I grew up, I also fell in love with electronics and computers. A love for both electronics and nature have been major themes throughout my life.
As I got older, I began to pay more attention to the environmental and energy problems our society will face for the foreseeable future. I started my websites, thesolarpowerexpert.com and freechargecontroller.org, because there is a sever lack of ‘do it yourself’ mentality in our society when it comes to electronics and alternative energy. Both of these websites are dedicated to helping people build their own solar systems and take their first steps into incorporating alternative energy into their lives.
Most people feel solar power is common sense. However, solar power is still very far behind oil, coal, and nuclear power. Why is that?
Unlike oil, coal, and nuclear power, which are mature industries, the solar power industry is still in its infancy. Solar panels have been around for decades, but prices have only reached economically feasible levels in the last 5 to 10 years. Coupled with this infancy of the solar market is the rapid explosion in innovative power control products and solar panels that has also taken place in the last few years. From a business standpoint, this all presents a great deal of risk. I believe this is the biggest reason why utilities, governments, businesses, and other large organizations have been slow to adopt the technology.
This is also a big reason why I advocate the adoption of solar technology at the individual, consumer level. Once the basic building blocks of a solar power system are understood, it’s not hard to build a simple solar system. It’s much easier for individuals to take advantage of the falling prices in solar products than it is for large organizations.
However, I would be amis not to point out our cultural heritage when it comes to oil. America invented the oil industry and that industry is highly coupled to our government. I think this single fact goes a long way in explaining Americas slow adoption of solar technology, as compared to other countries, like Germany.
What is the technical aspect of solar power which keeps it from outputting more power from panels?
The theoretical, maximum efficiency of a solar cell is around 33%. There are two reason for this. The first is polarity. Solar cells can only absorb light that strikes it from narrow range of directions.
The second reason is due to the light spectrum. Unlike the human eye, which can absorb light in a wide spectrum (red through blue), silicon solar cells can only absorb a narrow spectrum of light. Imagine the only color you could perceive was red. That’s a bit like what a solar cell is like.
There are of course a host of additional technology you can throw at a solar panel to improve efficiency, such as sun trackers, focusing lenses, etc, but this all adds complexity and cost. The trend for solar technology has been quantity over quality. If you can make the panels cheap enough, you can just cover more area rather than trying to get more efficiency per square foot.
If I decided to go solar to power my house, how long would it take to recoup my investment and have free energy?
That is the million dollar question. The simple answer is that a properly designed system should be able to recoup the investment in 5 to 15 years. The actual amount of time it takes to recoup your investment is highly dependent on geographic location and the tax incentives you can get from your local governments.
That also assumes that you go the conventional route of hiring a contractor for the install and purchasing a large grid-tie array of panels, which requires a large upfront cost of $10,000 or more. However, if you build your own DIY solar panels or install your own grid tie kit, the cost is significantly less, which means you can recoup your investment much quicker.
What is to keep solar panels from breaking during storms, such as hurricanes and tornadoes?
Quality craftsmanship, good installation, and a little luck. This is the biggest reason not to build your own system and to hire a professional instead. In order for your expensive solar system to pay for itself, it has to last for years. Longevity is key.
Most solar panels are constructed with tempered glass and aluminum frames in order to make them rugged. This also makes them heavy. The silicon solar cells used to construct a panel are very fragile, and they need a lot of protection in order to last for years. Many DIY solar panel builders need a few tries before they learn to make solar panels that are as good as the professional quality ones you pay a premium for.
What has been the most successful project in recent history to affect the future of solar power. Can you tell us about it?
‘Sucessful’ is the key word here. There has been a vast amount of innovation around solar technology in the last few years, but most of it is so new that it would be premature to call it ‘successful’. For example, some of the more profound inventions are:
- Plastic lenses that can be put over the top of a panel and instantly doubles its efficiency by polarizing the light at the quantum level
- Amorphous cells that can stretch and squish and are practically unbreakable
- Solar ‘paint’ allowing people to literally paint the side of their house and turn it into a giant solar panel
- Massive improvements in battery technology
- Less expensive MPPT charge controllers, allowing small solar panels to run more efficiently.
- Micro-grid tie inverters
Out of all these, I’d consider the last one, micro grid tie inverters, like the Enphase M190, to be both the most successful and the most influential on widespread solar adoption in the years to come.
These devices allow a home owner to upload power from their solar panels directly to the grid, removing the necessity for batteries and thereby lowering costs significantly. It’s estimated that as much as 25% of the capacity of the power grid in Germany is owned by homes and small businesses using solar panels and grid-tie inverters. These devices make a robust, flexible power grid that is practical, proven, and cost effective.
How does radiant solar heating work?
Radiant solar heat is a form of thermal solar. This is different than solar electricity generated by photovoltaic (PV) panels. Thermal solar uses black tubes filled with water to absorb heat from the sun. That water is then pumped into a radiant heating system (such as hoses installed under the floor of your home) to allow this captured heat energy to radiate into your home. This is an extremely cost effective way of making a dent in your heating bill and thermal solar systems are both inexpensive and easy to build yourself.
The drawback to these systems is that they are most effective in the summer, which is when heating is usually not desired. However, if designed correctly, you can pump the heat into your home during the winter and into your pool during the spring and summer (if you have one). They make extremely effective pool heaters.
How do you image the future of solar power of the next 30 years and how it will affect us.
As a large source of power for the utility grid, solar provides significant risk. There would be huge differences in electrical capacity between winter and summer. For this reason, I think solar will never be the power source to rival all power sources. Instead, it will be an important part of national alternative energy sources, which include wind, biomass, and others.
The largest advantages that solar offers is the level of independence and cost savings they provide to the home owner. Solar systems are infinitely scalable – which means that a 200 watt system works just as efficiently as a 1 megawatt system, and will often cost near the same in terms of dollars per watt ($/w). There are no other methods of electricity generation that fit this description.
For that reason, I am confident that widespread adoption of solar technology will take place over the next 30 years. Even if governments and large organizations fail to adopt solar power in ways that rival conventional power generation, homeowners will. As energy costs rise in the coming years, more smart grid equipment is deployed, and the costs of solar equipment continue to fall, a tipping point will be reached where it makes a lot of sense for the average home owner to invest in a solar installation. That point may have already been reached. If not, we are very close.