Today’s post is about selecting between a hot water solar collector and a photoelectric solar collector, and the decision points involved in doing it.
When deciding on what sort of solar collector to deploy we considered cost, efficiency, return on investment, convenience once the installation was complete, and impact on the appearance of our home.
First we considered the cost. We could install a basic solar water heating system for a couple of thousand dollars by doing the work ourselves. A solar electric power panel system would cost in the range of $2,000 for a small system self installed all the way up to $60,000 for a professionally installed system. But we found that in order to take advantage of the tax and utility company bonuses we would need to have installed by a licensed contractor.
Efficiency relates to how well the system turns the sun’s heat energy into usable energy for our home. In this area the solar water heater is much more useful, being able to convert about 90% of the sun’s rays into heat energy. Today’s solar electric systems range from 12 to 20% efficient.
The return on investment can depend a lot on how an installation is done. In our case we already have a quite effective water heater so even if we did install a great solar preheating system it still couldn’t save us that much money. (A water heater also needsa backup system in place anyway for over cast days.) On the other hand we can certainly use an inexpensive source of electricity and after the various incentives it looked like we would be at break even for our electric roof in about four or five years. As far as the convenience, both solar electric and solar hot water systems take a little continuous maintenance. The hot water system would take more, especially in the summertime when they can overheat.
Since the south side of our house is the front of the house the appearance of a solar collector became an important consideration for us. Neither type of system could be hidden, but we were more comfortable with flat panel collectors for this reason. If it had been on the back of our home we would have seriously considered vacuum tube hot water methods.
When all the ideas were evaluated we decided that a large solar electric collector was right for us. I hope this article was at least somewhat helpful.