Solar Power

Solar power, Specially Grid Interactive solar power is very expensive. My new house with Quadruple play is to be powered by solar power. But because PV panels and inverters are so costly it's not practical to install enough panels to meet the full power demand. The solution then would be to draw the shortfall from the grid.

Grid interactive inverters are the perfect solution, they use delta conversion to draw the shortfall from the power lines or to supply the excess back to the grid. Unfortunately these inverters are darned expensive here. The next solution would be to use a simple sine wave invertor and a transfer switch. That way when the solar panels cannot supply the requirement current the system would switch over to the utility company.

The trouble with auto transfer switches is that there is a small time period (usually about 200 milliseconds) when there is no power at all. That's the time it takes for the switch to disconnect one source and switch to the other. But there is a solution for that too. It's known as the closed circuit transfer switch. There the new connection is made before the old one is disconnected. Trouble is they are also expensive.

There is a third alternative that I am considering. To buy a delta conversion online UPS and to hack it. If I can somehow couple the batteries that are being charged from the solar power system with the battery bank of the online UPS , I have a near perfect solution.