I had a solar guy come out last week to see what my options were for photovoltaic electricity. It turned out to be more of a can of worms than I expected. Before he arrived I did some basic homework.
Google’s Project Sunroof is a tool that helps determine a property’s potential. Solar panels don’t have to be mounted on a roof, but that’s a good place to start. The standing seam metal roof has excellent solar exposure particularly in the back and is ready made to receive panels. I asked my tenants to look at their electric bills. $47 per month was the average with the highest month being $65. Service fees, taxes, and other administrative costs made up a significant chunk of those bills so $25 was owned even before any power was used.
If I assume an electricity bill of $60 a month a standard grid tied solar package will cost $9,000 up front after government subsidies. There’s a thirteen year pay back period. And after twenty years there will be $6,000 in savings. Financially, it makes no sense to spent $9,000 to save $6,000. There are lease and loan programs for solar equipment that don’t require any money up front, but I don’t like debt or complex transactions with binding long term contracts and legal fine print.
Out of curiosity I typed in $400 a month (I know many people who have electric bills of that kind) and the numbers changed dramatically. With $30,000 up front the system would pay for itself in only six years and save $85,000 over twenty years. The problem with my property is that it simply doesn’t use enough power for solar to work given the established industry parameters.
Again, just out of curiosity I typed in $25 a month (the lowest amount possible) and there was no pay back or savings at all. Zero.
Let’s get back to the solar guy who walked the property with me last week. I explained that I had already done most of the things required to radically reduce the house’s energy demand and that my tenants were frugal users of power. I’m not motivated by saving money because the power bill is already really low. I’m not preoccupied with “saving the planet” because buying a lot of expensive complex technology with creative financing isn’t the most likely way to solve environmental problems. Instead, I want the property to be able to ride out difficulties – both financial and physical. I want a house and garden that can function pretty well even if all sorts of other things in life go wrong – from unemployment to lengthy power failures like what’s continuing to plague Puerto Rico seven months after a hurricane took down the entire power grid on the island.
Could a couple of off grid solar panels run a DC submersible well pump and fill a surface holding tank? This would eliminate the need for batteries, inverters, or a complicated grid tied computer controlled system. Equipment is available on the market for about $1,500 and can be installed in a single day. Grundfos is the highest quality German manufacturer of such units.
The same could be done for the attic exhaust fan. One small solar panel wired to a fan with a DC motor would do the job since the fan only ever runs on hot sunny days. Kits are on offer at the big box stores and online retailers for as little as $220.
It would have been illegal to run electrical conduit to the garden shed/guest cottage without a permit. (Pulling a permit and enduring an inspection from the authorities is on the same list as surgery without anesthesia.) So I use a few portable battery bricks to power cell phones, tablets, and LED lights with USB plugs. As a couple of batteries are being used another couple are being recharged in the main house. There’s no reason a mini solar setup couldn’t charge the batteries during the day for use at night.
The fridge is eight years old and has a life expectancy of another few years, give or take. It would make more sense to replace the old fridge with a super energy efficient unit rather than try and generate more power from an expensive solar system. In an emergency situation life can go on without a fridge, particularly if shelf stable alternatives are kept in the pantry. People forget salami, hard cheese, pickles, sauerkraut, jam, and dozens of other foods were invented to preserve perishables in an era when mechanical refrigeration didn’t yet exist. Home canning of meat and soup works just fine when a freezer isn’t functioning.
The solar guy understood my perspective and said he could work with me on an off grid back up system. But I was going to be in a legal gray area. Anytime any form of permanent electrical work is done to a house it triggers an interaction with officialdom. So we’re going to have to tread lightly and cherry pick which things we do, and which we don’t. A portable plug-and-play solar generator is my most likely choice.
It might be simpler to install additional rain water catchment tanks to compliment the existing 5,000 gallon unit that’s already in place. Water flows in from the metal roof by gravity. Water flows out the bottom spigot under its own pressure. Do I really need a solar well pump? I prefer the path of least resistance with the fewest bells and whistles.
Should we all finance our way into $30,000 solar arrays so we can charge our electric self driving cars? Or do we just get bicycles and live in places that don’t require incessant driving?
I believe we can run a respectable civilization on solar panels and windmills. I just don’t believe a society that runs mostly on alternative power would look exactly like the one we have now. So I’m opting out of complexity and debt and doing my own thing quietly on the sly. I don’t expect many followers.