I've been wanting to install a solar power system for years. Actually during my high school years I wanted to work in solar power research, but when I got to college the computer room distracted me enough to become a software engineer instead. At the moment it doesn't seem practical to install a solar power system because I live in a rented house. But the last few days I pondered how to set up a small scale solar power system, enough to perform charging for my electric motorcycle, maybe drive the laundry machines, etc. Additionally I'm looking at a CNET article, 'Smart' electric grids to ease zap from plug-ins?, which discusses issues which might arise with widespread use of electric vehicles.
The CNET article is talking about V2G (Vehicle 2 Grid) systems .. "...a system that would essentially allow plug-in hybrid electric vehicles, in conjunction with battery-charging stations, to store energy at charging stations so they could recharge in 10 minutes at any time, taking from the electric grid during off-peak hours and giving electricity to the grid during peak hours...." Generally I am totally against V2G systems because of the difficulty with getting energy on-board an electric vehicle. My thinking might change if there were a battery charging system which can easily push energy into a battery. As it is the battery charging systems I'm aware of involve long charge times (my motorcycle takes 4 hours to fully charge). The peak electricity demand is in mid-afternoon as afternoon heat causes people whose houses are poorly insulated (hence they heat up) to crank up the air conditioner driving electricity demand sky high.
The V2G advocates think that they can tap the electricity in PHEV battery packs during peak time, and then replace the energy later. But suppose they begin tapping PHEV packs at 2:30 through 4PM, deplete the packs during that time, and then start charging them again at 4:30 PM. If it takes 4 hours to charge the PHEV packs and they can't start charging until 4:30 (past peak demand) then what are the workerbees who leave the office at 5PM going to do with a depleted car?
Also, would the PHEV fire up the gas engine during the time the grid is stealing energy? In other words, would the grid, by stealing energy from PHEV's, cause the electricity generators on those PHEV's to kick on and start burning gasoline in order to power the grid? If so that would be an undesired side effect of the move to PHEV's.
In any case back to my motorcycle and thoughts about a solar power system.
Typically when I ride the motorcycle it involves two trips per day. One trip in the morning to get to work, the other in the afternoon to return home. There is a charging station at work, I plug in on arrival, the bike is charged by mid-day, etc. Then on the return home the motorcycle is depleted and I plug in at home.
It's not feasible to install a solar charging station at work.. so I'd install one at home.
A solar charging station at home would be a battery bank, solar panels, a charge controller, and an inverter. The inverter would provide the 120v AC required by the motorcycle charger. The inverter could also provide AC for the washer/dryer in the garage which I could also drive off this same system. The charge controller makes it so the solar panels do not overcharge the battery bank.
This sounds simple to put together and would cost in the neighborhood of $3,000.
The only wrinkle I can think of is that the battery bank can't recharge until the sun comes up. If I'm arriving home at 6pm, recharge the motorcycle off the battery bank, and it finishes charging the motorcycle at 10pm (or thereabouts) the home battery bank would remain discharged until the morning when the sun comes up and the solar panels start recharging. But, assuming the home battery bank is lead-acid, this is bad for the life of the battery pack. Lead acid batteries are hurt when they're left partially discharged and it's best to start them charging right after use.
Maybe solar power users already have a solution for this as they face a similar issue. Consider a house with solar panels and a battery bank... during the day the batteries are charged up, but at night they don't produce power. Any power used by the house at night depletes the batteries which won't be able to charge until the next morning. There must be a known solution to this.
The solution I can think of is to have the home battery bank have a grid-connected charger. But this rather defeats the purpose of the solar panels, doesn't it? And it doesn't solve for off-grid systems.
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