Solar Panels in Georgetown

“It was a no-brainer.”  Marc Mulzer is talking about the bargain he got on a solar array installed on his roof last week.  Mr. Mulzer is from Munich, where solar is a “huge, huge deal.”  The German city has pledged to use only renewable energy by 2025, and Mr. Mulzer estimates that every third house already sports photovoltaic panels.  The solar industry has been very robust in Germany, in spite of a rather unremarkable quantity of sunshine.  Last year almost half of all the solar installations in the world were in Germany.  When Mr. Mulzer came to Texas thirteen years ago he wanted to take advantage of our abundant sunshine but was discouraged by the high cost of panels and lack of financial incentives from the state.  This year he got lucky.

The city of Georgetown received $50,000 for solar incentives from a Department of Energy grant and was able to offer a few fortunate applicants a rebate of $2 per watt of photovoltaic capacity installed.  Mr. Mulzer’s system can produce 4 kilowatts, meaning he received an $8000 discount from the city on the price of his system.  His solar installer, Longhorn Solar, offered him another hefty rebate for being their first customer in the area.  Mr. Mulzer’s out of pocket cost will be only $3000 for a system that will provide almost half of all the electricity he needs for decades.  He also expects to take advantage of a $900 federal tax credit when he pays his income tax next year.  The solar panels will pay for themselves in about four years.

There are sixteen solar panels on the south-facing part of the Mulzer’s roof.  Any time the sun is shining each panel is producing about 250 watts of electricity.  That direct current travels to an inverter box on the side of the house where it is converted to alternating current for household use.  If the panels are generating more electricity than the house is using, the excess feeds into the electric grid where it can be used by other Georgetown customers.  When the panels are feeding the grid, the meter is running backwards.  At night when the sun is not shining, or anytime they are using more electricity than the panels can produce, the Mulzers will get their electricity from the grid like everybody else.  This is called a grid-connected system, and there are no batteries required.  Switching back and forth from solar to the grid is automatic; the Mulzers will never have to think about it.  With no moving parts and hail-resistant glass, the panels will be essentially maintenance free for 25 to 30 years.

Why should the city be interested in helping people buy solar panels?  The answer is peak demand.  On a hot summer afternoon when everybody turns on their air conditioners, wholesale electricity prices get very, very expensive.  During times of near brown-out, the wholesale price can be much higher than the retail price, so the city is losing money to keep the lights on.  If enough houses have solar panels cranking out electricity on those same hot afternoons, it’s like an extra power plant on the rooftops of the city.  This “distributed generation” means a lower peak demand on the coal and gas-fired power plants and less need for the city to shell out exorbitant sums for emergency power.

The grant that funded Mr. Mulzer’s panels has been used up, but Kathy Ragsdale, Conservation Services Director for Georgetown Utility Systems, is developing another in-house program of solar incentives that would not depend on federal grants.  Those new rebates are not yet available to city customers.  However, customers of Oncor can sign up for incentives immediately and be ready to generate their own solar electricity this summer.