[Naked Harry (OP)]

John got in touch with us to ask:

"I read somewhere that over 50% of energy is wasted between power station and house/business due to heat losses. I recall this as being one reason why it's difficult to run underground high voltage cables. Is it really that much, and how much would it cost to 'fix the problem' and have local generation?

Secondly, how much did the Tesla battery in Australia cost, and would the construction of some of those be cheaper than all the energy wasted (or the cost of subsiding generators to to produce electricity) when there is a surplus (I'm thinking particularly of wind farms)? Does it work as expected?"

A leading question to really sink your teeth into. What do you think?

[Bored chemist]

I read somewhere that over 50% of energy is wasted between power station and house/business due to heat losses

Then you read something wrong.
Those losses are normally under 10%.

[Bored chemist]

how much did the Tesla battery in Australia cost

There's a wiki page
https://en.wikipedia.org/wiki/Hornsdale_Power_Reserve
 that says
"During 2017 Tesla, Inc. won the contract and built the Hornsdale Power Reserve, for a capital cost of A$90 million".

That's about £48M

Does it work as expected?"

The same wiki page says
When the Heywood interconnector failed for 18 days in January 2020, HPR provided grid support while limiting power prices. This event was the main contributor to Neoen's €30 million ($A46.3 million) operating profit from Australian battery storage in 2020

That's a pretty good return on investment.

[alancalverd]

50% of the energy of any fossil fuel cannot be converted into electricity due to the thermodynamic limitations of practical boiler design. Pretty much the same applies to nuclear power.

Transmission losses depend on voltage and distance. The principal supergrid voltage of 400 - 500 kV (varies by country) results in fractions of a percent loss per mile, whilst local distribution at  11 kV can lose 1 - 2 % per mile.

Local generation is capital-intensive and electrically inefficient: 400 kV switchgear needs a lot of space, so "community" generation is usually at 11 kV or below. However if you have a local source of fuel (e.g. farm waste) and can usefully distribute the waste heat rather than blow it off to the atmosphere, it makes economic sense.

The problems associated with underground cables are principally economic. You have to dig a geologically stable trench every inch of the way and cross roads and rivers, and the armored, insulated  cable is very expensive, whereas you can sling a cheap bare  conductor  400 meters between pylons to do the same job, a bit of earth slip won't break anything, and faultfinding and maintenance are very easy.

[Bored chemist]

Thermodynamics do not, in principle, limit the efficiency of transmission of power.

In general, a big power station will be more efficient than a small one.
It's also easier to "reuse" the "spare heat" from a big power generator than a small one.
https://en.wikipedia.org/wiki/Cogeneration
Though there's a trade off - it's easier to move that heat about over short distances.

[Petrochemicals]

This may be what the source you where reading too was referring to.

https://www.google.com/amp/s/blog.spiritenergy.co.uk/homeowner/is-electricity-cheaper-at-night%3fhs_amp=true

Exessive capacity without demand.

[alancalverd]

It's also easier to "reuse" the "spare heat" from a big power generator than a small one.

That's a sort of oxymoron! Battersea power station used to supply steam and hot water to the flats across the river at Dolphin Square, but multi-megawatt stations generally do not feed many other establishments  because of the cost and losses associated with transporting the waste heat over longer distances. Small generators, on the other hand, can be built close to or even in the middle of villages where the supply and demand for heat are balanced. There are many examples in Sweden where the power plant has been integrated into a local community development, surplus electricity is exported efficiently to the grid, and heavy domestic electrical appliances such as washing machines and cookers have a 3-phase spur supply, improving overall efficiency and reducing installation costs.

The steaming pavements of New York had the advantage that the  city was being developed along with the gas, and later electricity, grid, so installing steam pipes from big generators was no problem, but the disruption of established British cities for such a project  would probably be unacceptable.

[evan_au]

I read somewhere that over 50% of energy is wasted between power station and house/business due to heat losses.

Most of those heat losses are in the power station. For Australia, that means the inefficiencies of burning fossil fuels.

In particular, for the grid-scale battery on the  South Australia/Victorian border, the power will mostly come from Victorian brown coal, which is a water-saturated mess. A lot of energy is consumed evaporating the water before the remaining brown coal is dry enough to burn. So the efficiency of fossil fuels in Victoria & South Australia will be even worse than most places in the world (except those burning peat bogs or frozen tar sands in Canada - those are truly atrocious!).
 
Solar panels on your roof don't suffer losses from long-distance transmission.
- South Australia has lots of land that would be suitable for grid-scale solar - either photo-voltaic or salt storage.
- Photo-voltaic generation is somewhat inefficient due to the efficiency of current mass-produced solar cells, but at least it doesn't produce greenhouse gases while it is generating.
- The salt storage is somewhat inefficient due to storage as heat, but at least it doesn't produce greenhouse gases while it is generating.
- South Australia is also well positioned on the "Roaring 40's" airstream to produce lots of continuous wind energy. It doesn't produce greenhouse gases while it is generating, either.

[Bored chemist]

but the disruption of established British cities for such a project  would probably be unacceptable.

And yet, it has been done.
https://www.vitalenergi.co.uk/our-work/sheffield-city-district-heating/

[alancalverd]

True, but note the scale: 19MW of electrical power, heat for 3000 premises - a village within a city. And Sheffield has a reputation for tearing up city streets to install tramways: I suspect the steam pipe was laid alongside a tram track - anything to use steel! I can't think of a gigawatt station (other than Battersea, now an art gallery) that has been similarly used.

[Bored chemist]

The CHP system was in place before the supertram.
The disruption was a pain in the proverbial, but surely everybody is used to roads getting dug up from time to time?

Wat would be interesting would be do look at the economics of a hydrogen fueled CHP system on a scale  suitable for running my house.
You could (for extra credit) compare it with an air-source heat-pump system.
Feel free to make any assumptions you like  regarding size of house , weather etc.

[alancalverd]

Wat would be interesting would be do look at the economics of a hydrogen fueled CHP system on a scale  suitable for running my house.

If you are on mains gas, you already have 60% of what you need, in the boiler. A gas-powered motor-generator would be quieter than a diesel and shouldn't cost much more than £10k for a 20kW machine.  If you cook with gas, you might get away with 10 kW or less.

[alancalverd]

surely everybody is used to roads getting dug up from time to time?

I often wonder about the true economic cost of road works. If the road isn't actually dangerous, "improvements" are either a complete waste of money (M6 Toll) or allow traffic to increase until it is saturated again (M25). What is he cost per mile to the national economy, of restricting a motorway to 2 lanes at 40 mph whilst "they" replace an undamaged  barrier that doesn't meet European standards of ugliness? 

Round here "they" enjoy  causing almost continuous traffic jams on all the main roads whilst they increase the width of the cycle path (but never prosecute cyclists for riding on the carriageway) , or pour concrete over the countryside so that empty buses can break down in the middle of a field. Not that it matters, because the "plan" is based on a Very Expensive Computer Model (reality is too cheap to consider) and somebody's brother in law has a contract. 

[vhfpmr]

never prosecute cyclists for riding on the carriageway

Daniel Cadden was famously prosecuted for cycling on the road instead of the cycle path in Telford. His conviction was overturned on appeal on the minor technicality that he had been found guilty of breaking a law that doesn't exist.

[wolfekeeper]

Wat would be interesting would be do look at the economics of a hydrogen fueled CHP system on a scale  suitable for running my house.

Small generators pretty much always suck balls for more than occasional use. They're noisy, inefficient, unreliable and high maintenance. There are very good reasons why we have electric grids and have large centralised power stations.

You could (for extra credit) compare it with an air-source heat-pump system.
Feel free to make any assumptions you like  regarding size of house , weather etc.

Air source heat-pumps typically cost less to run. Installation cost often tends to be high though.

[Bored chemist]

What is he cost per mile to the national economy, of restricting a motorway to 2 lanes at 40 mph whilst "they" replace an undamaged  barrier that doesn't meet European standards of ugliness? 

Zero; because it doesn't happen.

but never prosecute cyclists for riding on the carriageway

As has been pointed out, there's a good reason for that.

[vhfpmr]

but never prosecute cyclists for riding on the carriageway

As has been pointed out, there's a good reason for that.

It just saddens me that the more public money that gets wasted on cycle paths, the more irate motorists will get, the more road rage there will be against us cyclists who don't use them, and the sooner the pressure for the government to make them compulsory will become irresistible. Then we'll all have to use them, like it or not.

[alancalverd]

What is he cost per mile to the national economy, of restricting a motorway to 2 lanes at 40 mph whilst "they" replace an undamaged  barrier that doesn't meet European standards of ugliness?

Zero; because it doesn't happen.

www.roadtraffic-technology.com/features/feature67206/ When did they start putting concrete barriers on motorways?
This became policy by the Highways Agency in 2005 when its Interim Advice Note 60/05 (IAN 60/05) called for the use of rigid concrete safety barriers for motorway central reserves where annual average daily traffic (AADT) exceeds 25,000 vehicles a day.

Fascinating. An average of 1040 vehicles per hour means that the road must be pretty safe. The peak flow will be at least 5 times the average, so they will be passing at 60 - 70 mph without serious incident every day - precisely the kind of road that does not need a new barrier!

[Bored chemist]

What is he cost per mile to the national economy, of restricting a motorway to 2 lanes at 40 mph whilst "they" replace an undamaged  barrier that doesn't meet European standards of ugliness?

Zero; because it doesn't happen.

www.roadtraffic-technology.com/features/feature67206/ When did they start putting concrete barriers on motorways?
This became policy by the Highways Agency in 2005 when its Interim Advice Note 60/05 (IAN 60/05) called for the use of rigid concrete safety barriers for motorway central reserves where annual average daily traffic (AADT) exceeds 25,000 vehicles a day.

Fascinating. An average of 1040 vehicles per hour means that the road must be pretty safe. The peak flow will be at least 5 times the average, so they will be passing at 60 - 70 mph without serious incident every day - precisely the kind of road that does not need a new barrier!

You failed to address my point.

[Bored chemist]

Fascinating. An average of 1040 vehicles per hour means that the road must be pretty safe. The peak flow will be at least 5 times the average, so they will be passing at 60 - 70 mph without serious incident every day - precisely the kind of road that does not need a new barrier!

By this "logic" we should put a barrier on the roads which are derelict and have no traffic at all.