Solar energy is wonderful and I like to use it around the house a lot. It provides the electricity for our home, including enough energy to charge an electric car. It provides illumination, most of our hot water and we even use it occasionally to cook delicious meals. Even though it all comes from the sun, each form of use is unique.
SolaTubes for Light
In our case, perhaps the simplest and most direct use of solar energy is for daylighting. Every home has windows of course, but like many Southern Nevadans, we have added SolaTubes to provide more natural daylight in key areas that were a bit too dark during the day. They are a marvelous way to brighten a home.
Sun Oven to Cook
Another simple device is our sun oven. It works best on clear, sunny days. The outside temperature is not really a concern as long as the sunlight is strong. When it is shining brightly, angled reflectors focus light on the oven’s tempered-glass top, trapping heat in the insulated chamber. The food cooks perfectly as oven temperatures exceed 300 degrees. An automatic timer prevents over-cooking. It is called sunset.
PV for Electricity
The grid-connected photovoltaic (PV) system on our roof is also immediate, producing electrons as soon as light strikes the panels. Technology allows us to send extra, unused power back to the electrical grid in exchange for energy credits on our account. In effect, the grid acts as a 100% efficient battery. We use our solar energy during the day and the grid seamlessly fills in the gaps at night or on very cloudy days when our use exceeds PV production. This type of system is very efficient and unlike the previous forms of solar energy above, it is not a “use it or lose it” scenario.
Solar Thermal for Hot Water
Our solar water heating system lies somewhere in between. Thermal energy is quite different than electrical energy. Since it is not possible to send extra hot water back to the utility company for credit, those who can make the best use of solar-heated water when it is available will realize the greatest benefit. Families or businesses that use a lot of hot water are an obvious example, but timing plays a role too.
Nothing is immediate with solar thermal systems. It takes a while for the sun to raise the temperature in our storage tank, just as it takes a while for that heat to dissipate; and it will dissipate. A well-insulated tank can slow the process, but nothing beats timing when it comes to using solar-heated water.
Optimized by Simple Adjustments
In our two-person household, we have made some simple adjustments for optimal results. Our solar-heated water resource is usually greatest during mid-day, so the period between 11 AM and 2 PM is a good time to do laundry or run the dishwasher. Those activities can still happen at any time, we just choose to optimize our use of the sun’s energy when we can.
During the summer, we now turn off our gas-fired water heater backup from June through September, except when occasionally necessary. This bit of extra attention and manual intervention keeps the backup water heater from firing in the wee hours just before sunrise. We can still take a comfortable shower first thing in the morning with the water from the previous day’s solar harvest. Turning off the gas backup system completely for months at a time is a relatively new experiment for us but it is working marvelously, further reducing our already low carbon footprint.
My wife and I enjoy making these small adjustments in our routine to maximize the benefits of a solar-powered lifestyle. It is fun and also provides a greater connection with the natural cycles that surround us. Our investments in efficiency and clean energy make financial sense, but my greatest satisfaction is the contribution to improving our environment. It’s impossible to put a price tag on something that is irreplaceable. In that sense, solar energy is priceless. That’s why I like to use it around the house.