> - if you
>>> can find an economic way of doing it. However, even running the
>>> numbers on the back of an envelope will quickly show that it's not
>>> just uneconomic - it's hugely uneconomic.
>>
>> Care to share them?
>
> I lost the envelope. But calculate the cost of the batteries you'd need
> to support your day-time load. Then calculate the amount the interest
> you'd earn on the money if you didn't buy batteries. Then calculate the
> diffence in cost of the electricity you achieve through changing the
> times you draw power from the grid.
>
> Finally, take into account the very limited life of batteries.
>
> The numbers show that it's a no-brainer.
>
> Which is why the power generation industry isn't doing it already.
Power industry isn't doing it because their size in batteries can not be purchased at the local garage.
Okay, taking my fileserver, which requires 96 watts max and my LG995E CRT monitor which requires 72 watts max, that means 168 watts I need out of the battery bank, or 14 amps @ 12Volt.
So, to cover 7am to 10pm, I need to store 15x14 = 210 amp hours. In lead acid, this means 420amps hours.
Practically, that equates to 5x100AmpHr batteriess hour at $200 (old price), or $1,000. 10 year life span means costs 28c per day in depreciation. Loan costs is 6% atm or 20c per day.
Electricity savings are 15(0.1575-0.0554) =$1.53c. Net savings are $1.07c per day. or $3,905.50c over ten years.