The desire to be green exists in most of us I am sure. However, not all of us have cash on hand to “contribute” to the solar industry. What follows is the analysis of one family’s planning to use free solar energy without breaking the bank.

Preface:

My wife thinks I am a greeny weeny in my quest to harness the free energy from that big star out there. I say I am just trying to use Star Power. I like that name better than Solar Energy.

Being green is certainly a goal all of us should adopt. Available green energy options cost from cheap to ridiculous. Difficulty ranges from easy to difficult. A conservative at heart, my green options have to stand the test of at least basic financial scrutiny. An electrical engineer by trade, I am a brutal reviewer of the soundness of the various systems.

The Internet documents a large amount of do it yourself (DIY) projects. The home-brew approach is nothing new in the alternative energy crowd. I have a book from the early seventies that discusses most of the same things we see documented today. The Internet is a great library of these efforts. Your initial research will be rewarded with more data than you can digest in one sitting. Don’t fret. It takes a while and you need to watch out for some very incorrect information from folks who just don’t know what they are doing. The good news is many folks have done a fine job of documenting their experiments with real data available for your review. Very nice.

My stated goal is to harness “Star Power” to offset at least some of my energy consumption and do so with economic common sense.

Highlights include:

• Philanthropists Welcome
• Incentives
• Return on Investment
• Energy Payback
• Evaluation Criteria
• PV Solar Electric
• Wind Electric
• Thermal Solar Hot Water

Philanthropists Welcome

What we are about to reveal below is just how un-economic many of the alternative energy approaches are. Many folks still pour cash into systems that cannot ever hope to be cash positive in any reasonable amount of time. They know this and still choose to do it because of their honest desire to be “good” to the Earth. I applaud anyone who contributes their hard earned cash towards the reduction in energy consumption from fossil fuels, etc. without expectation of financial reward. This is what I will call “Environmental Philanthropy.” Bravo to all of you who do this and accept my sincere thanks for what you are doing for your fellow man.

Incentives

Unless you pay no attention to just about everything, you know there are exceptional financial incentives available in the form of tax credits and other benefits from Federal all the way down to local governments. These are OK, but there is a potential flaw in partaking of these benefits. You are spreading your costs to your fellow citizens in exchange for helping reduce energy consumption. Our elected representatives think this is an OK thing to do so we are stuck with it. In the case of federal tax credits, you are also financing it and putting the burden on your children in the future.

This is the way it is and I will be taking advantage of these credits if I can.

Return on Investment

If you take a closer look at these incentives you will realize they are very much an artificial stimulus for the various alternative energy suppliers and installers out there. Upon scrutiny you will see commercial providers rarely provide a cost effective solution for their green wannabe customers and, thus, rely on tax credits to help fund their operations. This is a form of corporate welfare. This is not to say the alternative energy industry does not provide good quality products with superb installation… they do. As we will discuss below, most have pricing that, even with incentives, provides a return on investment (ROI) that is beyond ridiculous.

Story time…

Once upon a time in the 1990s I was in Flagstaff, Arizona working with Lowell Observatory on a new telescope installation. I noticed a shop on US66 (yes, the famous Route 66) called “SOLAR ENERGY STORE.” Cool I thought. I made a point to stop by that store during a weekend break because I really was eager to critique the latest solar energy methods available. I walked in the door and what did I see? Wood Stoves… lots and lots of wood stoves. I love wood stoves too, but could not figure out why they were in the SOLAR ENERGY STORE. I asked a salesman where were the solar energy products? He said “We have not had those hear since the 1980s.” I reminded him the name of his store with a clear expectation of an explanation on my face. He said since the Carter tax credits expired in the Reagan years, solar energy was just not viable and not worth selling.

I blinked. I paused. “You mean your industry can only survive if subsidized?”

“Yup.”

I believe subsidies should help folks who cannot otherwise afford items get them if the result helps the whole. I do not think they should help prop up an industry that refuses to grow up and produce products that are financially sensible to purchase and use.

So, in the text below, tax credits and other benefits will be ignored and the systems rated for their ROI on their initial costs because it does not matter if the purchase funds are from cash reserves or from our children’s future. Only the selfish would evaluate ROI based on the net cost after rebates are applied. It is up to you ensure tax credits applied to your system return good value for those credits.

Here is the next point. If any equipment vendor suggests a return on investment of more than 3-5 years something is terribly wrong with this picture.

There is an old saying about poker players; If you can’t spot the sucker at the poker table, it is probably you. The same goes here. You should never accept return on investment periods for capital equipment more than five years with three years being more like it. It does not matter if the equipment can and does survive 20 or more years. If you break even just as the equipment’s life ends, who made the profit? Put another way, did the equipment ever save you any money (via reduced energy costs) or did the whole benefit just flow to the organization that sold you the gear by taking all your future savings up front. YOU are the one putting up your hard earned cash so you deserve all or most of the benefit realized from YOUR money. It does not matter where you obtained the cash be it savings, home equity line or other. Somehow or another you executed a financial transaction to get cash in hand. This investment needs to work for you.

You need to understand any business that tries to charge you so much money for an alternative energy system based on a return on investment scaled to most of the lifetime of the equipment is structuring the deal to benefit themselves, not you.

Energy Payback

If you have a little greeny weeny in you, be sure you understand how much energy it took to build, deliver and install the energy system you are planning. Things seem to be headed the right way in this regard, but you need to understand all your best efforts may result in a net energy loss which spoils the whole reason many invest into alternative energy in the first place.

Evaluation Criteria
For this post, the following criteria will be applied…

• Return on Investment
• Energy Payback
• Total System Cost
• Difficulty of installation

PV Solar Electric

It is no secret the cost of Photo Voltaic Solar Energy systems provide no practical return on investment for the investor. Where traditional energy sources are available, these systems are purely a philanthropic exercise. Vendors suggest ROI periods measured in decades. It amazes me customers with any business savvy whatsoever would accept this ROI from any investment short of, say, a house.

• Return on Investment – Decades which is hopelessly ridiculous. Ebay seems to have bare PV cells available for about $1/Watt which drastically reduces the installed price to $3/Watt and ROI, but not enough.
• Energy Payback – One to four years if operated full time… and getting better I sense. The Ebay “seconds” PV cells may eliminate this concern since you are using cells destined for the trash.
• Total System Cost – $10,000 – $50,000 and maybe more based on about $4/Watt. This assumes you are trying to replace the energy consumption of a typical home. You can scale the size down and realize less benefits. The cost per Watt goes up a bit, but the same ROI issues are true no matter how you scale the system.
• Difficulty of installation – The concepts are easy to follow, but this is serious electrical work and should only be accomplished by a licensed electrician with knowledge of PV Solar.

Wind Electric

If you have a windy wide open backyard a wind turbine might be sensible. I looked at various DC and AC approaches and find merit in many of them. My favorite wind turbine approach uses higher voltage three phase AC from the turbine all the way to the load point where it is rectified, regulated and applied to the load; The higher voltage requires less copper wire for the same net power transfer. The load can be a battery system and/or a grid tie inverter. The cost per watt are still pretty high at $4/Watt, but plenty of DIY efforts can tame this cost.

• Return on Investment – Dozens of years unless you put your own time into it and, perhaps, find components on the cheap.
• Energy Payback – I could not find data on Energy Payback for this approach. Like with PV Solar using slightly cosmetically defective or recycled components may help this greatly.
• Total System Cost – $1000 will get you started.
• Difficulty of installation – This depends on your electrical and mechanical capabilities. The AC voltage approach can and does use voltages well above the level than can kill you. A licensed electrician is essential.

Thermal Solar

Using heat from the sun has been around since time began. Nature offers many examples including cold-blooded animals positioning themselves to partake in the morning sun’s heat after a chilly night. Camping equipment vendors offer “Solar Shower” black bags which absorb heat and transfer it to a few gallons of water inside ready for a warm shower later. A good architect will design a house to make good use of Winter’s lower angle solar rays to heat a room with well placed windows and eaves. What the above examples imply is it is not very difficult to make use of free heat from the Sun.

Often the #2 energy hog in a house, the water heater is a logical focus for solar heating.

• Return on Investment – The Energy Industry seems to have the same game in play where they price their equipment at the level of your eventual savings thereby leaving you will little benefit. Fortunately solar heat collectors can work with low grade heat allowing for ample compromise in collector construction. Plus DIY is alive a well in the thermal solar realm leaving plenty of opportunity for the ambitious handyman. Most thermal solar assemblies rely on a storage tank. Money can be saved if you time your solar install with the end-of-service replacement of your water heater; For a few hundred dollars more, you can get a larger tank with built-in heat transfer coils ready for your later install of the thermal solar panels and associated plumbing (This assumes an indirect thermal system). Thermal Solar Collectors are possible to build at home thanks to their relative simplicity.
• Energy Payback – The materials needed for thermal collectors seem routine enough to not stress the EP too much. I don’t know the details though. It certainly takes energy to manufacture a decent hot water storage tank. However, as explained in the previous bullet, if you replace an aging water heater you are investing a regular maintenance expense into your system.
• Total System Cost – The Rheem Solar Water Heating products are north of $800 up to $2000 depending on model. I suspect with panels we are talking $1000-$3000. DIY on the panels can save big.
• Difficulty of installation – This is a plumbing task and, if you build your own collectors, a carpentry task. It might make good sense to let a plumber do the replacement of your water heater with your solar water heater. This way, you greatly reduce the risk of an incomplete job leaving you are your family without hot water. One important addition to the usual hot water heater connection is a water tempering valve. These are pretty expensive, but required if your solar install is a success as temperatures in the tank will be much hotter than you want for your home’s fixtures. Here again the benefit of a good plumber will make this install neat, tidy and functional.

You may have noticed, in the above words about thermal systems, the idea of replacing your water heater with a new unit rather than adding a thermal storage tank to an existing system. The goal here is to make use of the solar hot water as directly as possible. If you have the classic heat storage tank feeding a traditional water heater, that heater still needs to maintain the temperature of the tank during times of no hot water flow. If you, instead, use the one tank approach, the solar heat is directly heating and maintaining the temperature in that one tank. This maximizes efficiency. Plus the Rheem products have the usual electric back up during very cloudy days or moments of high demand. This important point will ensure your family will never notice a lack of hot water maintaining peace.

Conclusion

Of all the many possible ways of utilizing solar energy, the thermal system provides the best possible return on investment both in energy and dollars.