Re: energy in UK

Martin Brown <'''newspam'''@nonad.co.uk> wrote:

On 16/04/2025 23:49, Don Y wrote:

On 4/16/2025 3:11 AM, Martin Brown wrote:

Is the "cap" significantly higher than the "normal" rate?  Or, is it,
effectively, the "normal rate"?

>
The cap limits ordinary home users exposure to extreme market
volatility. It

 
Of course.  But, a consumer's idea of a "reasonable cap" and a
PROVIDER'S idea
are likely worlds apart!  Hence my question as to whether or not it was,
EFFECTIVELY, the normal rate (i.e., providers opting for as much as they
can get, within the current constraints)

 
It is better than any of the alternatives. I suspect at one point the
utility companies were at break even or even making a slight loss on
domestic customers when the gas price went up very high.
 
They compensated by hammering business users.

The 'price cap' was originally set up to prevent suppliers price-gouging
retail customers who weren't on fixed term tariffs.  They'd end up on the
default tariff which was often much higher than the shiny advertised tariff
- some of those customers had never switched tariff or provider, some not for
30 years.  The cap was set by some formula based on the wholesale price over
the previous 6 months.  Only those who had run off the end of their contract
were on the price cap, a relatively small number.  ie it was a true cap, and
most people were paying less.

Then Ukraine happened and the wholesale price exploded.  The price cap,
being based on the wholesale price 6 months ago, did not.  Because the price
cap was in law the maximum price that could be charged, everyone ended up on
the price cap.  So it became the maximum price and, because suppliers were
making a huge loss over the wholesale price, that's what they all charged.
(a good number went bankrupt too)

The next update the price cap went up massively, but the government stepped
in to subsidise consumer energy bills to limit the unit costs - effectively
a new lower cap.  That subsidy has ended, but the price cap logic (now
calculated every 3 months) is still what drives the prices most people pay.
Even though it was never designed for this scenario.

Businesses never had a price cap.  Small businesses often sign up for
energy in 3 year fixed term deals, and the ones some signed up to have very
high unit rates (>60p/kWh).  They had no choice to sign up because their
previous deal came to an end and otherwise they'd be disconnected.

My supplier has just offered me half price electricity at the
weekends. Only snag is their website won't allow me to accept their
generous offer - it keeps saying "something went wrong- try again later".

 
If there isn't a corresponding INCREASE in the weekday rate, it could
be a win.  They likely have surplus (weekend) capacity and are looking
to encourage users to consume that, instead of weekDAY capacity.

 
Yes the 5:2 ratio is very visible in the national power output graphs.

Some of those tariffs are a bit of a gimmick if you look at the numbers:
while there's some variation in demand weekend v weekday, there's much more
variation in supply based on the weather.  Some of the operators give you a
variable price based on wholesale (including free energy when it's sunny or
windy) which is more aligned with the actual balance.

Having solar panels is another way to get onto a ToU tariff. Even that
is gamed though. Much domestic PV electricity ends up heating domestic
water as the feed in tariffs are also based on crazy sums. There is an
aftermarket in diverters to exploit this loophole.
>
There are incentives to install solar PV but none for solar hot water.

 
You could, of course, use (PV) electrically heated water.  There are
myriad schemes to make better use of the energy available but few
see widespread use.

 
That is what the aftermarket diverters allow to happen. Through a quirk
in the Feed-in Tariffs it pays to do that and only export the excess.

It's not just FITs, without FIT you might get paid 5p to export and you pay
25p to import.  It's cheaper to divert that into hot water than it is to pay
to import to make hot water, or to burn gas at 6p for your hot water.

Obviously it'd be better to store it in a battery instead (to displace 25p
import during the night) but diverters are/were a cheaper alternative (or
for when the battery is full).  The price of batteries has fallen a lot so
it's becoming more attractive to have a battery now, if you have the space.

A personal favorite, here, would be to capture the waste heat from the
ACbrrr condenser and use it to heat swimming pool water; the liquid medium
would likely be a more efficient coolant than air sourced in a typical
condenser.  And, 100F pool water is delightful!

 
Outdoor swimming pools are not common in the UK. It is too cold -
although wild swimming in open water is on the increase since Covid.

Air to water ASHPs are the way a lot of people heat their swimming pools, as
it's cheaper than gas.  They run very efficiently into low-temperature water
(~30C).

It would not be implausible to have an ASHP where the refrigerant is taking
heat from a house and heating pool water - just need a heat exchanger of
refrigerant into water not air.  Could probably do it in a domestic A/C
system with some diverter valves in the refrigerant circuit.

The utility has been complaining that they have "too much" residential
solar capacity (the utility has a say in whether or not YOU can use
solar
and how large your installation can be)

>
UK allows up to 4kW solar generation on any domestic premises. More
than that

 
I don't think the *city* places limits on size of plant.  But, requires it
to reside on rooftops to avoid permitting, architects, etc. (of course).

The difference is that < 3.68kW you can just install PV with no permitting.
If you want to install more you need to fill in a form first.  The power
company could tell you to limit your export based on the capacity of the
local grid, but they can't refuse you point blank (you could just do 3.67kW
in the worst case).

Theo