The
plunging cost of solar PV means that it may now be half the cost of
grid-based electricity, according to some industry estimates. But the
economics of buying solar PV systems is still not clear for those who
cannot consume most of the energy produced on their rooftops,Our laser marking machine can
mark on metal and non metals. because owners of rooftop solar systems
are now getting paid little or nothing for the energy they export.
So
perhaps the time is approaching when the question should be asked: is
it worth considering energy storage? Is it cost effective? Should
householders go it along, or in a community group? And what are the
implications for other network users? Already, network operators and
generators are bleeding because every solar panel that is added reduces
demand and eats away at their centralised generation model. Batteries
would only accelerate that change.A simple model for the wake behind a wind generator is given.
These
were a series of questions that were posed by Gordon Weiss, an energy
expert from the consultancy and advisory firm Energetics at the recent
2nd Summer Study into Energy Efficiency and Decentralised Energy in
Sydney.
The first question is a bit of a no-brainer. As we wrote last Tuesday,Manufacturer of industrial grade outdoor solar lighting.
the cost of solar PV has fallen to the extent that it has achieved
“socket parity” in many places in Australia. Weiss thinks it’s even
better than that. His estimates of the levellised cost of solar PV is
between 12c/kWh and 14c/kWh, meaning that it is half the cost of
electricity bought from the grid.
See
the graph below for an illustration of these costs. For the energy and
technology wonks, Weiss bases his assumptions on two different system
sizes, assuming 14 per cent capacity factor, a 7 per cent discount rate,
and a 30-year economic life.
This
leads to the next problems. Generating electricity at this price is a
no brainer when most of it can be consumed on the premises.
However,
failing some clever and precise orientation of solar panels to the
east, north and west, that is not possible for most households, who find
that they have to export much of their electricity back to the grid. At
best, they are getting the wholesale prices paid to coal-fired
generation, mostly around 6c/kWh. They lose money on this transaction.
This graph illustrates the problem.Find lampshades for table, floor and Lamp shade in
lots of styles and materials. Even on a 1.5kW system, a lot of
electricity can be consumed at a 40c/kWh discount to Origin Energy’s
peak rate, but much of the electricity produced by the rooftop system
has to be exported.
So
what to do? Either achieve a further reduction in solar PV costs per
kW, or shift the output of the panels so that less solar output is
exported, and less grid power is imported. To shift the output means
either to move the timing of household use – in the same way the time of
use tariffs are designed to do – re-orient the panels, or consider
battery storage.
Weiss
has run some numbers on the battery storage option, and they are
illustrated in the graph below. They are really only designed to be
indicative numbers. The consumption numbers are based on a large home
with plenty of consumption, and some may disagree with the technology
costs, both for solar PV and battery storage, which are evolving quickly
anyway. The laser cutting machine is one of the most useful tools in a modern shop. The
point is to provide a useful illustration for the choices that will be
made, and for the critical debate about the shaping of our energy systems that must surely follow.
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