Random thoughts on load-shifting and whole-house UPS

[DamonHD]

Hi,

I'm just thinking about a modified version of something like SMA's Sunny Backup-System and how it might make sense from other points of view such as load-shifting to reduce overall CO2 emissions.

But I wonder if any of you that have time-of-day metering and an export arrangement for your local microgeneration get paid more more exporting units are times of high demand,

ie whether you could potentially help load-level the whole grid for a bit of cash, a little like the V2G schemes floating around.

Does anyone get paid more to export at peak demand times?

Rgds

Damon

[Jon Miller]

Hello Damon,

In the UK, with what I have researched about exporting tariffs for micro generation systems, the best available is net metering with someone like nPower.  That is to say you get paid the same rate on economy 7 and thus more during the day.  I think a demand based pricing system is possible with todays technology, you can get networks for computers now that make use of house hold wiring.  I am sure this can be applied on a large scale but weather its in the electric companies best interests currently.  

I am not sure that the net efficiency of storing power in batteries to sell on during times of higher demand is 100% in terms of CO2 once things like embodied energy and energy to recycle the batteries in question are taken into account.  Would be interesting to find it out if this is the case but i would not like to be the person to do it.

How is the new solar system getting on?

   

[DamonHD]

Hi,

Yes, I'm not sure how the emboddied energy, etc, changes things, though it may be better with (say) new Lithium battery technology which can cycle almost indefinitely by comparison with lead-acid.  And maybe a cycle or two's worth of ultracap would help.

PV system's best was about 2 days ago with 4.7kWh for the day, but today looked like being a washout since we started the day with an inch or two of snow on the grid-tie panel.  However we now have bright sun and may pass 1kWh for today!

My little ~80Wp off-grid system with near vertical panels shrugged off the snow sooner and was actually producing more than the 1.29kWp system until the afternoon.

Rgds

Damon