what size system do I really need?

strider3700 · 05-13-12, 04:08 PM

I'm anal about tracking my power usage but not amazingly frugal about it although my wife would disagree.

Anyway's yesterday was my lowest single day's usage ever. 14 kwh in a 24 hour period. This was the first real spring day this year, with no Heating at all, no clothes in the dryer(clothesline was in use) and quick reasonable showers. I didn't have specific tracking of the hot water power usage but looking at my past records the lowest it could have been was 4 kwh which happens on days where we're not home. More likely it accounted for 6 of that 14 kwh. I know the computer never went into sleep mode and accounts for 2.4 of the remaining 8. fridge, freezer, a bit of lighting and vampire must account for the rest.

When I move to my new house, I'm seriously thinking of putting in a solar setup to cover a good chunk of the houses usage. Electricity there is expensive compared to here at roughly 18 cents/kwh Also on the plans are solar hotwater, and a wood boiler for heat of both space and domestic hotwater.

So if I can get and keep the houses usage near 10 kwh/day how big of a system do I really need to be 100% solar in a grid tied system, making excess during the summer and drawing in the winter? I'm sure there must be info on how to calculate this but I haven't seen much from the sites trying to sell me the equipment.

05-13-12, 04:08 PM	#1
strider3700 Master EcoRenovator Join Date: Dec 2008 Location: Vancouver Island BC Posts: 745 Thanks: 23 Thanked 37 Times in 30 Posts	what size system do I really need? I'm anal about tracking my power usage but not amazingly frugal about it although my wife would disagree. Anyway's yesterday was my lowest single day's usage ever. 14 kwh in a 24 hour period. This was the first real spring day this year, with no Heating at all, no clothes in the dryer(clothesline was in use) and quick reasonable showers. I didn't have specific tracking of the hot water power usage but looking at my past records the lowest it could have been was 4 kwh which happens on days where we're not home. More likely it accounted for 6 of that 14 kwh. I know the computer never went into sleep mode and accounts for 2.4 of the remaining 8. fridge, freezer, a bit of lighting and vampire must account for the rest. When I move to my new house, I'm seriously thinking of putting in a solar setup to cover a good chunk of the houses usage. Electricity there is expensive compared to here at roughly 18 cents/kwh Also on the plans are solar hotwater, and a wood boiler for heat of both space and domestic hotwater. So if I can get and keep the houses usage near 10 kwh/day how big of a system do I really need to be 100% solar in a grid tied system, making excess during the summer and drawing in the winter? I'm sure there must be info on how to calculate this but I haven't seen much from the sites trying to sell me the equipment.