[wolfekeeper]

Actually, heat pumps generate 2-5 times as much heat as the electrical energy is used, and electric cars are much more efficient as well, so yes, overall energy use is indeed set to plummet. That's the whole point.

18%ish in the UK, I guess with it being a small distance in-between places.

If you mean:  "Costs for the transmission and distribution of electricity typically account for 16-20% of the typical domestic electricity bill." that's not the same thing as efficiency.

[Petrochemicals]

Actually, heat pumps generate 2-5 times as much heat as the electrical energy is used, and electric cars are much more efficient as well, so yes, overall energy use is indeed set to plummet. That's the whole point.

For the heat pump, do you have any real world experience from anyone for the 2 to 500percent efficiency? From what I have read it comes in at about 200 over the year. Problem is that at times when heating is most required during the winter the efficiencies are lower. Who needs central heating when it's 35 decrees C out side! I think the whole point is something like the heat exchanger for air changes, if your house is airtight enough you can save something  like 90 percent of costs.

.

18%ish in the UK, I guess with it being a small distance in-between places.

If you mean:  "Costs for the transmission and distribution of electricity typically account for 16-20% of the typical domestic electricity bill." that's not the same thing as efficiency.

ah that make sense then

This difference in the generated and distributed units is known as Transmission and Distribution loss. Transmission and Distribution loss are the amounts that are not paid for by users

[alancalverd (OP)]

Every part of the cost of generating and distributing electricity is paid for by the user. Who else? It isn't a charity!

It's wrong to talk about heat pumps "generating" 200% energy. They actually generate very little heat if the motors and pumps are efficient. What they do is move heat energy from place to place, and generally manage to move 2 - 3 times as much energy as they consume in doing so.

The source to drain efficiency of a car depends principally in the efficiency of the prime mover. In the case of an i.c. engine, it's around 40%. For the foreseeable future, it will be about the  same for electric cars - the prime mover just happens to be somewhere else, polluting the upper atmosphere.

[Bored chemist]

For the foreseeable future, it will be about the  same for electric cars - the prime mover just happens to be somewhere else, polluting the upper atmosphere.

It seems a pity that you can't foresee changes.

The rest of us recognise that renewables have been making a large, and increasing contribution for some time.

https://www.theguardian.com/business/2020/jan/07/renewables-beat-fossil-fuels-greenest-year-uk-energy

[alancalverd (OP)]

Worth reading David Mackay's seminal book  withouthotair.com/download.html. The last paragraph of p 238 makes the point.

The Guardian article, like so many, confuses electricity with energy. It only accounts for 25 - 30% of our energy consumption at most.

But we are wandering away from the subject here. The question is whether EoN are actually supplying me with 100% renewable electricity at all times, not some time inthe future but right now. Because they are charging me (and many others) for it.

[wolfekeeper]

Actually, heat pumps generate 2-5 times as much heat as the electrical energy is used, and electric cars are much more efficient as well, so yes, overall energy use is indeed set to plummet. That's the whole point.

For the heat pump, do you have any real world experience from anyone for the 2 to 500percent efficiency? From what I have read it comes in at about 200 over the year. Problem is that at times when heating is most required during the winter the efficiencies are lower. Who needs central heating when it's 35 decrees C out side! I think the whole point is something like the heat exchanger for air changes, if your house is airtight enough you can save something  like 90 percent of costs.

I don't have any first hand experience, but I've been following the technology.

For example, the Mitsubishi M-series reversible heat pumps apparently work particularly well for heating purposes down to low temperatures. There's graphs here:

https://www.greenbuildingadvisor.com/question/visualizing-mini-split-performance-data

So from the graphs, at 5F (-15C), the heat pump retains 80% of its nameplate COP (about 3.7 or so), which isn't bad. However, it also loses power output, 50% at 5F, but only loses 20% at 32 F (0C). The loss of power is generally a slightly bigger problem than the loss of efficiency.

[evan_au]

Fossil fuels decreased by 42%; Gas increased by 38%

I'm not quite sure how to interpret these two lines in the graph...
- Last time I checked, Gas was a fossil fuel (unless UK is using a very different gas than Australia...)

[alancalverd (OP)]

I have a 160 sq m building heated by airsource heat pump with underfloor coils at 30°C and domestic hot water at 50°C.

When it works, the overall COP is certainly above 2 but the whole system is depressingly unreliable - the transition from physics to simple engineering  in a refrigerator is brilliant, but the design of a modern heat pump has added expensive and fragile layers of programmable sophistication to a very simple principle.

I expect a refrigerator to maintain 5°C for 20 years, and they do. What I want is to maintain a well-insulated music studio at 18°C to keep the instruments in tune and the players awake.  What have to buy is a gizmo that can deliver pretty well any temperature in any part of the room at any time of day, with different programs for each day, provided that a nursemaid is on call to check the feed water pressure,  thermostat batteries, water grit filter is clear,  no leaves sucked into the condenser, umpteen flow valves lubricated, diverter valve not seized..... 

Years ago I built three clinics around the most sophisticated  MRI machines on the market. Not a hint of trouble from the capital machinery, or the kitchen fridges, but in 10 years we never had the entire cooling and aircon systems all working properly at the same time.

[alancalverd (OP)]

Fossil fuels decreased by 42%; Gas increased by 38%

I'm not quite sure how to interpret these two lines in the graph...
- Last time I checked, Gas was a fossil fuel (unless UK is using a very different gas than Australia...)

I think "science journalism" is an oxymoron, like "military intelligence".

[wolfekeeper]

Years ago I built three clinics around the most sophisticated  MRI machines on the market. Not a hint of trouble from the capital machinery, or the kitchen fridges, but in 10 years we never had the entire cooling and aircon systems all working properly at the same time.

I can't speak to the (un)reliability of the particular brand of equipment that was installed.

[Petrochemicals]

Years ago I built three clinics around the most sophisticated  MRI machines on the market. Not a hint of trouble from the capital machinery, or the kitchen fridges, but in 10 years we never had the entire cooling and aircon systems all working properly at the same time.

I can't speak to the (un)reliability of the particular brand of equipment that was installed.

If you get a small heat pump, a Heat recovery unit, an insulated and airtight home you can achieve a Cop of 30. I imagine these are the homes that cost 10 pounds a year to heat.

To compare to other "systems"
Say you have a heat pump rated at COP = 2.5 (maximum permitted under SAP)
Outside temperature 1C (so the heat pump may avoid frost), inside 21C

instantaneous heating by 20C

HRV providing 0.35 ach (volume of air is 202m3)

Energy recovered 293W (o.35x0.33x volumex63%x20C)
energy used 10W
COP = 29.3 (2930%)

This is a strong indication that it is far far easier to save energy than it is to produce

http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3017#Comment_39416

[alancalverd (OP)]

It's true that heat recovery is the key to energy conservation. Little point in using a heat pump to warm the air if you then throw away your asset by opening the window!

That isn't strictly a COP measurement since you can have an entirely passive HRU which returns 80% of exhaust heat with no power input - infinite COP? What you have done is simply improve the effective insulation of a ventilated building.

[Petrochemicals]

Actually, heat pumps generate 2-5 times as much heat as the electrical energy is used, and electric cars are much more efficient as well, so yes, overall energy use is indeed set to plummet. That's the whole point.

18%ish in the UK, I guess with it being a small distance in-between places.

If you mean:  "Costs for the transmission and distribution of electricity typically account for 16-20% of the typical domestic electricity bill." that's not the same thing as efficiency.

I guess that the discrepancy is due to power not supplied to the grid, such as emergency reserve and extra power supplied to the grid that the customers do not draw off.

https://en.m.wikipedia.org/wiki/Operating_reserve

That is a lot of energy.

[wolfekeeper]

Cost and energy aren't the same thing. Energy use sets a floor for costs, but costs are usually more to do with paying personnel needed to do something.

[evan_au]

Cost and energy aren't the same thing.

This website suggests that costs of solar power have reduced by a factor of 5 in the past 10 years.
- The author looks at a few trends, and suggests that the production cost of solar energy declines by about 30% every time the industry doubles the capacity manufactured, due to the "learning curve" effect
- Lower costs means that the rate of manufacture is increasing; this model assumes that the rate of installed capacity is growing at 16% per year (compound growth).
- While the price of coal-power has not declined over the same period (and, if we are honest, the cost of ill-health due to coal power has increased over that time)
See: https://rameznaam.com/2020/05/14/solars-future-is-insanely-cheap-2020/

Of course, before we shut down all fossil power plants, we need to deal with the fact that the Sun shines longer in the Summer, and not at all, at night....

[wolfekeeper]

Wind blows stronger in winter, and less in summer, and blows at night. In conjunction with grid batteries, vehicle to grid technology, and renewables from waste streams, it seems to me that the UK's electrical generation can go zero carbon.

[alancalverd (OP)]

Wind blows stronger in winter, and less in summer, and blows at night.

Not true. "Surface" wind (anything below 1000 ft above local surface, i.e. the stuff that makes electricity) ) is strongly influenced by convective mixing, which is maximum when the sun shines. Persistent winter fog in the UK is due to the arctic anticyclone, with very little wind - and maximum electricity demand..

[Bored chemist]

Not true. "Surface" wind (anything below 1000 ft above local surface, i.e. the stuff that makes electricity) ) is strongly influenced by convective mixing, which is maximum when the sun shines.

So, you finally worked out that it's not powered by the rotation of the earth.
I guess that's progress.

[Petrochemicals]

Wind blows stronger in winter, and less in summer, and blows at night.

Not true. "Surface" wind (anything below 1000 ft above local surface, i.e. the stuff that makes electricity) ) is strongly influenced by convective mixing, which is maximum when the sun shines. Persistent winter fog in the UK is due to the arctic anticyclone, with very little wind - and maximum electricity demand..

I disagree, but it appears that wind turbines have been specified up for this summer wind, meaning that they appear unable to harness the winter wind. Shore breezes are renowned anyway, land heats during the day and cools at night meaning the direction changes. Shores are probably very good for the namby pamby wind turbines we are installing

https://www.britannica.com/science/sea-breeze

[wolfekeeper]

Wind blows stronger in winter, and less in summer, and blows at night.

Not true. "Surface" wind (anything below 1000 ft above local surface, i.e. the stuff that makes electricity) ) is strongly influenced by convective mixing, which is maximum when the sun shines. Persistent winter fog in the UK is due to the arctic anticyclone, with very little wind - and maximum electricity demand..

Nice theory, but no. What wind turbine conspiracy theorist told you that? Because they're wrong.

Wind power is consistently higher in the UK in winter, and lower in summer:

You can see the trend over the last year here:

http://gridwatch.templar.co.uk/

But the trend has been found back to 1979 (the earliest they looked) and climate models indicate it will continue:

https://www.carbonbrief.org/uk-wind-power-can-help-meet-peak-winter-demand-study

We're currently in the summer portion, so wind is generally lower right now. Solar is doing well though.