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The future of energy generation and storage

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basilio said:
I have a hydronic heating heating that works exceptionaly well. Is there a reasonably practical way to replace the current gas fired water heater with another source ? (It could be an option for many other similar customers)
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Switching between any combustion sourced heat (gas, oil, wood, coal, whatever) is straightforward but there's some complexity involved with electric heat pumps and the issue comes down to water temperatures.

Gas, oil, coal, wood etc work pretty much the same whether the water is heated to 80 degrees or 40 degrees. Any efficiency difference is minor when you're starting with a flame temperature of 1950 degrees C. For reasons of cost most hydronic systems are thus designed to operate at relatively high water temperatures. That keeps the pipes and radiators smaller.

Heat pumps however are far more efficient at lower water temperatures and efficiency drops of dramatically at the sort of temperatures common with gas (or oil or wood etc) hydronic systems. It can be done most certainly but the usual workaround is larger radiators operating at lower water temperatures in order to maintain heat output to the room.

So the short answer is that retrofitting a heat pump as the heating source for a relatively high temperature hydronic system tends to be problematic unless the radiators happen to be over sized which usually they aren't.

For situations where lower temperatures are involved, such as normal household hot water or heating a swimming pool, it's dead easy and purely an economic question.

I've been heating my own hot water with a heat pump since 2009 with zero problems thus far (and there's no booster in the system by the way). I'm about to move house however, I'll resume packing boxes in a few minutes after posting this (it's a mind numbing task......), so won't get to see how long that system lasts etc. New house has nothing fancy when it comes to energy (indeed it's pretty much the opposite but fear not, Smurf will fix that that in due course.... ).
 
SirRumpole said:
Looks like there may be quite a bit of excavation for the ground pipes. Expense ?
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Yeah, they can lay them in a shallow trench horizontally if you have the space which is cheaper, or in vertical drill holes if you have a smaller back yard.

Or you can just use Air based heat exchangers, but they aren't as efficient but they still work well, thats basically what a reverse cycle air conditioner is, thats why when you are running your Air con in Heat mode, Cold air blows out the unit out side, it is stripping the heat from the air.

 
There are exceptions but the vast majority of heat pumps are air sourced since that's the cheapest and easiest way to do it, albeit not the optimum for efficiency.

For heating water for household use though a Sanden heat pump will achieve a COP of 4.5 so that's 4.5 kWh of heat for each 1 kWh of electricity used. Many reverse cycle air-conditioners achieve similar results for space heating. So while you could improve further, they're already pretty good these days.

Higher temperatures such as for hydronics is where it gets more difficult though.

As for heat sources other than air, the Hydro Tas office building in Hobart had a heat pump system using the river (sea) as the heat source for many years although it has since been replaced with an off the shelf air-sourced system mounted on the roof.

Not sure if they still do but for a long time Hobart City Council was using the warm water in sewer pipes as the heat source for heating a large public swimming pool with the heating done via a heat pump system. With the warm input it achieved very high efficiency. Not sure if that's still running or not.

My 9 year old air-sourced water heating heat pump achieves a COP of about 3 in practice.
 
I look forward to when Vanadium Redox Flow Batteries become mainstream for residential. To me it will be like buying another piece of furniture with the added bonus of it producing something usable.
 
With regard to my previous posts about water heating I must apologise for an omission.

As has been drawn to my attention, the Victorian government has already mandated gas connection for all new homes in the state. That's right, you can not in practice choose to not connect gas to a new home in Victoria and that applies regardless of economics.

Electric hot water? Nope, you can't have that.

Solar with electric boost? Nope, that's not allowed either.

Heat pump? No, can't have that. Keep trying....

Your choice is either gas or cold showers! You can put some solar panels up too if you like but you're having gas like it or not and will be charged for doing so since that's the law.

I will confess that I have never liked the broad attitude of Victorian governments to most things, the state has long seemed to have a ridiculous number of rules for just about everything, but this one "smells" rather strongly to me and even more so when I mention the same government funding the installation of new gas pipes which private companies then charge for the use of and make profits from. That smell's getting rather strong and warrants investigation not by a gas fitter but by ICAC or whatever the equivalent organisation is in Victoria.

I'm not opposed to governing but it's getting a bit ridiculous when government decrees how to warm the bath.

To put some numbers on it, comparing a modern heat pump to gas, the end use efficiency of the heat pump results in 30% lower fossil fuel consumption even if we assume that 100% of all electricity it consumes is supplied from the least efficient plants in the grid. On any more realistic scenario it's closer to a 50% saving. And so the reason new homes are forced to use gas is? See my bit about needing an investigation because it sure does smell.

At least WA, SA and Tas are reasonably progressive with all this. Imperfect but at least looking to the future not the past.

I don't hate the gas industry but I do lament consumers being forced to use it in a circumstance where there is no sound economic, resource or environmental justification for such a policy. That's blatant industry protection, nothing more and nothing less.
 

That is completely absurd, anti-competitive and totalitarian.

I expected the Liberals to protect their industry mates, but as you said, this completely stinks.

I have never had gas connected to any house I've lived in and don't want it.

Fortunately I'm not in Victoria.
 
To clarify the situation in Vic and what the rules say:

If there is reticulated gas available in the street then for a new house you cannot install:
  • Conventional electric hot water
  • Solar hot water with an electric booster
  • Heat pump hot water
If the supply of electricity to the system is connected to the mains (which for 99.99% of homes in areas also having gas it will be).

In practice and assuming you want a normal supply of hot water that leaves gas with or without also using solar energy as the only realistic means to heat the water for the vast majority of consumers.

"Electric" Smurf doesn't hate gas, for the record there's a gas cooktop in my kitchen, but I sure don't like policies which dictate what consumers can and can't do with no valid reason. That's just over-governing and industry protection dressed up as having something to do with saving the planet.

Banning conventional electric systems for new homes might make some sense but there's nothing wrong with solar or heat pumps from an environment or energy efficiency perspective that's for sure.
 

Is Victoria a Liberal State? I thought Andrews was Labor, my appollogies.
 
sptrawler said:
Is Victoria a Liberal State? I thought Andrews was Labor, my appollogies.
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No they are Labor.

It has long been the case though, regardless of which party is in government, that Victoria seems to make a point of having rules for things.

Just something I noticed years ago and it has always been the case.
 
My guess is that their logic has been:

Coal is bad.

Most coal in Vic is used to generate electricity and coal is the largest source of electricity = electricity is bad.

Water heating is the second largest household use of energy in Vic after space heating.

OK then we will ban new homes using any form of water heating involving electricity.

Without having done the maths which, if they did do them, would reveal that heat pumps in particular are a good thing not a bad one.
 
It sounds like really dumb politics to me, a bit like someone putting 6Kw of solar on their roof and then putting in gas hot water, gas cooktop and gas oven.
Just shows Andrews`isn't very smart, which the East West Link $1billion cash throw away hinted at, but this actually proves the point.
He is a goose.
 
This is heading down a similar path to the dills who run the water supply in metro NSW.

In the 80's they went around and ordered people to remove water tanks from their houses if they were connected to water and sewer network. Those who did not comply were threatened with fines.

The attitude was "We have plenty of water in the dams and we want to charge you for using it"

Now it is a requirement to have a water tank plumbed into new buildings and we have a huge desalination plant sitting idle and costing the state millions in maintenance every year.
 
Very limited transmission capacity between Vic and SA today. Also minimal wind in SA and not much sun.

End result was almost total reliance on fossil fuel generation within the state and of note is that oil-fired plant (diesel, kero) was heavily utilised with all such plant maxed out at one point (excluding the SA government's "backup" plants which remain off).

So that's Angaston, Lonsdale / Port Stanvac, Port Lincoln and Snuggery power stations all had a pretty decent run today and reached maximum capacity whereas most days they do absolutely nothing at all.

There are conflicting theories as to why some the gas-fired stations weren't running anywhere near capacity. I don't know for sure what the truth is so I won't speculate but the theories / rumours circulating are either:

(1) traders deliberately holding back supply and trying to push the price up.

(2) they couldn't physically get enough gas to run more heavily so no choice.

I don't know for sure so no comment but it sure did push the price up.
 

Sure, keep the old boilers running untill alternatives have been put in place, but as most coal stations are now privately owned how is the government going to force the operators to keep them running ?

They are all pretty old now and the maintenance costs must be pretty horrific. Replacing them, with combined cycle gas systems would seem a viable option.
 
SirRumpole said:
Sure, keep the old boilers running untill alternatives have been put in place, but as most coal stations are now privately owned how is the government going to force the operators to keep them running ?
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That will be the next big political football, it is in the private operators interest, to close down steam plant.
With renewable's, they save on maintenance, labour and fuel costs, and they seem to have disavowed themselves of any responsibility for system security and stability.

SirRumpole said:
They are all pretty old now and the maintenance costs must be pretty horrific. Replacing them, with combined cycle gas systems would seem a viable option.
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I would think it doubtfull, there are adequate gas reserves, to replace the amount of base load in question.
 
Surprising nobody, the Andrews Labor government in Victoria behaves erratically on energy policy.

The Peoples Republic of Victoria. The Victorian government now dictating how householders may or may not power their own hot water tanks!

Electricity will be nearly as expensive as in SA, already the most expensive in the world.
 
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