It’s an interesting problem that I believe has a moving target since in
some places you get paid retail for your excess electrons but in other
jurisdictions you get paid a fraction of retail. The power companies
if they had their way would pay a pittance for your excess and then
sell you back the electrons at retail.
There is some justification for this since they don’t always need
your excess. Having too much excess power but no control over
when it’s being offered can be a big problem. If you have a bright
windy day and lots of solar and wind being dumped into the grid
and then get a sudden drop in wind and a cloud rolling overhead
the system will need to have peaking plants on standby to take
over the load. Idling these plants is expensive, maybe more
so than just suppling the power from traditional sources.
A grid that had distributed power storage and access to several ideally
clean energy sources would end up being the most stable. If you have
your own battery bank you can keep the lights on during a power failures
for sure but you can also run on your own ‘free’ electrons, sell the excess
to the grid if you have them, buy them back if you need them but maybe
at a lower off peak rate and potentially offer them back at a premium if the
grid asks for them.
This would allow for basically five price points:
$0.00 You don’t need the grid, the grid does not need you.
Here the grid is operating below optimal with room to move up but
not down.
$low-buy You do need the grid, the grid has excess.
Here the grid is operating below optimal and can efficiently offer
you more electrons.
$high-buy You do need the grid, the grid is peaking.
Here you have run low and the grid is operating above optimal
and drawing on other, maybe stored sources to make up the difference.
$low-sell You have excess and the grid has the capacity to accept.
Here you have excess and the grid is operating above optimal and
can save money buy accepting your extra.
$high-sell You have excess and the grid is peaking so needs extra.
Here you have extra and the grid is peaking and requesting extra
from stored sources, you offer some of your stored energy in
exchange for a higher value.
So in my estimation it is the bi-directional grid tie with with distributed
local storage and net metering is a the win-win situation.
There was a lot of discussion some time back about Vehicle to Grid
(VTG) solutions where electric cars become part of the distributed
storage. If you integrate vehicles and possibly stationary batteries
you could reach a point where there was enough storage to shut
down some of the dirty generating stations entirely, not just the peaking
plants.
Lawrence
> On Sep 22, 2015, at 12:12 PM, Robert Bruninga via EV <ev@lists.evdl.org>
> wrote:
>
> -----Original Message-----
>>> That's 1% to 4%. Better than most banks. And FAR better for the
>>> future since it displaces X amount of coal burning.
>
>> I'll bet a cup of coffee that stationary panels going to a set of
> batteries used as a dump pack for the golf cart would still financially
> outperform the roof-mounted option.
>
> When Can I collect the cup?
>
> Only if the Golf Cart and dump-pack are FULLY discharged every day.
> Because only then are you using the solar panels. A solar panel just
> sitting there in the sun connected to a fully charged battery is providing
> ZERO return on investment.
>
> That is why NET metering is the best economics hands down. You get 100%
> of the energy all the time, every day, no matter how much you use.
>
> People forget that battery systems are not only very inefficient, require
> maintenqance, but whenever they are fully charged, then the solar panels
> are providing nothing in return for their investment. And since battery
> systems have to have oversized solar panels to make up for cloudy days,
> then by definition, every fully sun day, then all the excess solar energy
> beyond full charge is simply wasted.
>
> My conclusion is that any use of batteries for storing solar energy wastes
> $2 of every $3 invested in the solar system. Grid-tie wastes none of it.
> You get full retail value for every watt that falls on the panels no
> matter where you use it.
>
> Bob, WB4APR
>
> You can use cheaper panels that get maximum insolation, and the only
> concern for the dump pack is total lifetime cost per kWh in and out --
> weight or volume or similar concerns are irrelevant.
>
> A significant fraction of the electric vehicles on the road are already
> solar powered; EV owners are statistically much more likely to have
> rooftop solar generation than others. Except as a gimmick or an
> engineering challenge or in unreal fringe cases (extraterrestrial
> planetary exploration), carting the panels around with you is the most
> over-the-top wasteful way to get to a "green" car. It's pure conspicuous
> consumerism --which is perfectly fine if you can afford and appreciate the
> luxury...just don't pretend that it's saving the planet or that it makes
> good financial sense.
>
> b&
> _______________________________________________
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> Read EVAngel's EV News at http://evdl.org/evln/
> Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
>
_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Read EVAngel's EV News at http://evdl.org/evln/
Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
