Tesla Batteries

That is peanuts if the investment usable life is 20-30 years, so just $1000/year. So you have to save that amount compared to alternate heat sources, such as direct electric heating. .

Burying plastic pipes just a few meters just a few meters below ground is a messy thing. It is OK for a new installation before building the house, but as a retrofit, you are going to destroy your garden. In addition, you need a large parcel, you might not get enough heat from a small suburban parcel.

Drilling deep (100-150 m) wells into the bedrock and you could have your own heat well on every small suburban parcel.

Reply to
upsidedown
Loading thread data ...

I guess they would say that, after shelling out thousands on the system. Even with the uk feedin tariff, where home solar was paid a premium for surplus, it still took around 15-20 years to break even on the original cost. That doesn't take into account panel failure, which can cost up to 1000ukp to replace, scaffolding etc and that's if the original installer is still in business and can be found. Also, reduction in output by 5-10% per annum. Typical load factor, ie: name plate rating vs actual op averaged over a year is rarely better than 10% here in the uk

Plan to install solar at some stage, but it will be home built and installed, depending on a good deal on the panels. As for the data, various reports, including from the uk government on things like load factor, initial cost, reliability etc. For some here, little more than a virtue signalling exercise for the hipsters, while they pay through the nose for it.

Not against it, but it has make sense economically and wild optimism doesn't make the sun shine :-)...

Chris

Reply to
Chris

How do you work around the laws of thermodynamics? The best outcome is that your heat-recovered incoming air is at the mean of the indoor and outdoor temperature, so you might recover some heat but the "efficiency" of your device can never exceed 50%.

Reply to
+++ATH0

y. Have you looked at the numbers? Where did you get your data?

There are people here in this group who have solar panels and can tell you exactly how well they are working. The UK has a very different climate tha n here. In fact, the US is large enough to have very different climates ac ross the country. They are installing commercial PV solar where I am in ce ntral VA which is east coast and not particularly sunny like the desert. R esidential is not subsidized, but since you can reduce your bill kilowatt f or kilowatt it is easy to make a solar system pay for itself.

You sure sound like you are dead against it. Why can't you see that the nu mbers work differently for other people than yourself?

Rick C.

+-+ Get 6 months of free supercharging +-+ Tesla referral code -
formatting link
Reply to
gnuarm.deletethisbit

he

air

Heat exchangers work by passing the two heat sink flows in opposite directi ons. So the cold air is warmed gradually eventually meeting the incoming h ottest air and the hot air is cooled gradually eventually meeting the incom ing cold air so both streams can approach the temperature of the other. Th ere is always losses and there has to be a temperature delta to make the he at flow, so you never get it all, but you can get a lot of it.

Rick C.

++- Get 6 months of free supercharging ++- Tesla referral code -
formatting link
Reply to
gnuarm.deletethisbit

How big?

Size matters. My 4T air-source heat pump will cost somewhere between $6500 and $12000 to replace (in the next week). A ground-source heat pump would be a complete waste of money here. Other than noise reduction, I don't think there is any advantage to the units at the more expensive end of the range, above, either.

Reply to
krw

Around here, we have maybe a foot of topsoil and then rock. That would be hard to drill.

But the climate is very mild. We don't have a/c and it never freezes here near the coast. Our usual gas+electric bill is around $100 a month.

We don't have many million dollar houses either!

--
John Larkin         Highland Technology, Inc 

lunatic fringe electronics
 Click to see the full signature
Reply to
John Larkin

:

the

no,

.
e

ish

ump

Where is here? I'm sure there are many places where ground sourced heat pu mps would be very cost effective. I would need to see numbers associated w ith any given installation, but I didn't choose a different system because of the cost. I didn't buy the ground-sourced system because they wouldn't quote me a number. They expected me to sign a contract to do the work rega rdless of what the cost turned out to be. Looking back, I should have gott en them to bid the contract in two portions, the fixed price, well defined work part and the variable cost, don't know how much work it will be part.

I was so taken aback by the apparent ease of him asking me to sign an open contract that I didn't think to discuss it further and asked him to leave.

Rick C.

+++ Get 6 months of free supercharging +++ Tesla referral code -
formatting link
Reply to
gnuarm.deletethisbit

Southern US. Atlanta, to be more specific.

I don't think there is anywhere they're cost-effective if you include all costs, including the cost of money.

yeah, right? We had an HVAC contractor give us a quote then say that he couldn't do the work and that a friend would but he used a different manufacturer and that quote wasn't binding. Yeah, that was going to happen.

Reply to
krw

:

s> >> >>

or the

rtino,

old.

here

ablish

y

t pump

a

F enough that it would make straight electric backup heat unrealistic. Lot s of people do that here too, VA/MD, but I think it's on the cusp. By the time you get to NY you need to have some other backup heat to make it affor dable and then you need to consider the system cost. My heatpump/oil burne r cost $7,000 while a heatpump/electric backup was $5,000. Here you'd be l ucky to get your money out of the oil burner. In NY it's a slam dunk. It also seems to produce better heat... actually warm.

very cost effective. I would need to see numbers associated with any give n installation, but I didn't choose a different system because of the cost. I didn't buy the ground-sourced system because they wouldn't quote me a n umber. They expected me to sign a contract to do the work regardless of wh at the cost turned out to be. Looking back, I should have gotten them to b id the contract in two portions, the fixed price, well defined work part an d the variable cost, don't know how much work it will be part.

Cost of money is pretty low these days. I don't know how much fuel cost a ground-system can save you, but it will be more than just not using expensi ve backup heat. They are cheaper to run all year long.

en contract that I didn't think to discuss it further and asked him to leav e.

The quote is always non-binding... it's just a quote. It's the contract th at is binding.

Rick C.

---- Get 6 months of free supercharging ---- Tesla referral code -

formatting link

Reply to
gnuarm.deletethisbit

It all depends on the COP

formatting link
versus temperature _difference_ between the cold and warm side. When the temperature difference is too large, the COP drops to 1, i.e. only the electric power running the heat pump will emerge on the warm side. As a rule of thumb, keep the COP above 3 for significant savings.

The warm side temperature depends on the way heat is delivered to the room, with floor heating +30 C to +35 C should be enough. Other delivery systems require higher temperatures and hence larger temperature differences and hence lower COP.

On the cold side. th ground water temperature would be +0 C to +4 C. OTOH, the winter air temperature varies much more. If the air temperature is most often above +0 C, the air sourced heat pump is more effective. If the air temperature remains for longer periods below 0 C, ground based system make more sense.

Reply to
upsidedown

I used to live in the bay. Now, I could not possibly afford the homes I used to own.

Google, Facebook and others have raised home prices throughout the region. There are plenty of million dollar properties in the bay. Gentrification has increased home prices in SF. Many companies supply busses to transport their employees from SF to the bay. You need to get an appraisal to find out how much your home is worth. You might be surprised.

The weather in SF is moderated by the ocean. You don't need much heating or A/C.

Further north, the climate is more severe. House constuction has improved the sealing so heat losses are reduced.

This creates a problem where stale house air has nowhere to go. The only solution is to open windows to get fresh air for ventilation. This defeats the purpose of the sealing and increases heating costs.

The solution is a Heat Recovery Ventilation (HRV) system as I described above. Heat Energy Recovery (HEV) systems may be required in different climate regions. Google tells you all you need to know.

Stay healthy. Get fresh air in your home.

Reply to
Steve Wilson

On Sunday, January 13, 2019 at 11:37:32 PM UTC-5, snipped-for-privacy@downunder.com wr ote:

s> >> >>

or the

rtino,

old.

here

ablish

y

t pump

a

pumps would be very cost effective.

't even get that in my glass of iced tea full of ice! Around here water te mperature is much warmer than that, central Eastern Seaboard US.

Actually, here these systems don't depend on the water temperature unless t hey are tapping a well. Usually they depend on the ground temperature. No real water involved. At least that's what I was told for this area. Why dig 100's of feet when you can just dig a trench? Every place is different in that respect though.

Rick C.

---+ Get 6 months of free supercharging ---+ Tesla referral code -

formatting link

Reply to
gnuarm.deletethisbit

n:

pump

.

t

or

s

My house is paid off so that means older than 30 years and not of the herme tically sealed construction. No need for heat exchangers, the ventilation is built in, lol! There are enough small air leaks around windows and such that I don't have to worry about radon either.

Rick C.

--+- Get 6 months of free supercharging --+- Tesla referral code -

formatting link

Reply to
gnuarm.deletethisbit

It has got worse since that 2014 article. Not enough generating capacity and some of the aging kit is becoming prone to breakdown in winter.

formatting link

Left hand grey graphs are daily, weekly, monthly and yearly demand.

It was *much* worse than that implies. They were literally paying some very big users to drop off entirely and stay off. The likes of smelting plants that have to be put into a safe lower power but still fairly hot state and cannot be switched on and off on a whim. They needed to keep the refineries running or there would have been other shortages as well!

Another complication was that it was found that some NHS hospital beancounters had very cleverly put their gas and electrical supplies on a cheaper interruptable tariff to save money (reasoning that supply shortage based interruptions would never happen).

formatting link

They had to drop even more at peak times but they had to literally shut down entirely the biggest users and pay them to use as little as they possibly could consistent with not damaging their idle plant.

The links work well most of the time and allow easier load balancing.

It can happen when there is a blocking high in mid winter that a large part of Europe gets similarly very cold weather at the same time. The clue is in the name "Winter". Siberian winds can reach the UK when this happens and we are *never* prepared when it does. Snag is that a nice calm blocking high can take down all the wind generation and cause very cold temperatures to develop with clear skies overnight.

The more southerly climates stay nice and warm in winter but large parts of highly populated northern regions end up in the icy grip of winter. The entire of the UK is latitude 50 or above. We have a maritime climate most of the time but if the wind is from the East we get very cold air from the cold continental landmass and snow.

Smelters, metal refineries, glass making or any continuous process that is energy hungry and needs tightly controlled conditions. Certain loads are historically used for load balancing - mainly electrolysis which literally can be switched on and off at a moments notice (some require a certain holding current to make sure the electrolyte stays molten) but the brine ones are the ultimate load balancers and very tolerant.

It may be. What is a typical US electricity cost per kWhr. It is about

12-15p in the UK (10-12c) but with a daily 30p standing charge as well.

It is for the people who have installed solar PV under that deal.

That is interesting. So although the Tesla power wall says it can work installed outdoors at -10C it is doing that by consuming enough power to keep itself at some more battery friendly temperature. Makes sense since chemical reactions vary exponentially with ambient temperature and diffusion will be slower in the cold too.

--
Regards, 
Martin Brown
Reply to
Martin Brown

:

the

no,

.
e

ish

ump

OK I know nothing of the details, but in theory a ground sourced heat pump should reduce your cooling costs in the summer. (You are starting with cooler fluid..)

George H.

Reply to
George Herold

The age of your infrastructure is not the issue. We are discussing shutdow ns due to daily usage peaks.

This is good, but limited. There is only a week of useful info and that is hard to view. The daily graph is just for one day which makes it hard to discern a clear pattern. It appears there are two peak, morning and evenin g with the evening peak being more pronounced.

What is clear from this data is that there is a period of 8 to 10 hours whe n demand is at a minimum. Shutting down industry that must run 24 hours a day is clearly not the right thing to do. Rather industry that currently r uns in the day time but can instead run at night is the load that needs to be time shifted and potentially not shut down at all.

? on

See my comment above regarding the timing of load shedding.

Sounds like something that should be addressed.

ply-could-be-cut.html

Then that is either not a peak usage issue, but rather a total generation c apacity issue or someone is full of BS. If the country is not willing to b uild generation capacity then there will be electrical shortages. I bet a lot of people still have kerosene lamps, lol!

Yeah, until they don't work at all!!!

Why is it that the UK is in the mess. Clearly a complete planning failure.

Yeah, what's your point? That there is no realistic planning in the UK?

I'm not real clear on the connection to winter cold. I thought you didn't use electricity for heating?

If a load can't be shut down during the peak times, then don't shut it down . Which industries can be shed only during the peak times?

Actually I think many of your industries can be shut down during peak times . They used to have an aluminum electrolysis plant near here and a friend who worked there said they could ramp it up and down pretty much at will. He told me how once there was some reason for the crew to hump and they inc reased production by some large amount for one shift and one shift only. T hat means proportionally higher power consumption. So clearly if it can be ramped up over one shift it can be scaled back over one shift.

Not sure what p and c are. Here it varies with region but a number I often see is $0.12 average. What is a standing charge?

Not when the goal is to save money. If the unit is outdoors it also needs to be cooled in the summer. More money. They typically talk about garage installation, but then my garages are not heated either, but one is in a ba sement which is not subject to the outside extremes. If they insulate for winter then they need an active cooling system.

Rick C.

--++ Get 6 months of free supercharging --++ Tesla referral code -

formatting link

Reply to
gnuarm.deletethisbit

r the

tino,

ld.

ere

blish

pump

p

Yeah, you are pumping heat downhill rather than uphill. Much easier. If y ou can get enough heat through you might be able to dump the compressor.

Rick C.

-+-- Get 6 months of free supercharging -+-- Tesla referral code -

formatting link

Reply to
gnuarm.deletethisbit

y

owns due to daily usage peaks.

is hard to view. The daily graph is just for one day which makes it hard t o discern a clear pattern. It appears there are two peak, morning and even ing with the evening peak being more pronounced.

hen demand is at a minimum. Shutting down industry that must run 24 hours a day is clearly not the right thing to do. Rather industry that currently runs in the day time but can instead run at night is the load that needs t o be time shifted and potentially not shut down at all.

? on

!

upply-could-be-cut.html

capacity issue or someone is full of BS. If the country is not willing to build generation capacity then there will be electrical shortages. I bet a lot of people still have kerosene lamps, lol!

e.

s

e

t use electricity for heating?

a

wn. Which industries can be shed only during the peak times?

es. They used to have an aluminum electrolysis plant near here and a frien d who worked there said they could ramp it up and down pretty much at will. He told me how once there was some reason for the crew to hump and they i ncreased production by some large amount for one shift and one shift only. That means proportionally higher power consumption. So clearly if it can be ramped up over one shift it can be scaled back over one shift.

en see is $0.12 average. What is a standing charge?

o
e

s to be cooled in the summer. More money. They typically talk about garag e installation, but then my garages are not heated either, but one is in a basement which is not subject to the outside extremes. If they insulate fo r winter then they need an active cooling system.

So in summary you don't understand the UK electricity industry at all yet y ou want to tell us what to do. Again.

NT

Reply to
tabbypurr

You are all missing the point. No matter what kind of heating system you use, you still lose heat when you need to open the windows to ventilate the old stale air.

A Heat Recovery Ventilation (HRV) system can recover from 70% to 85% of the heat in your exhaust air and bring fresh air into your home.

In the summer, the situation is reversed. You want to keep the hot outside air from entering your home, and still exhaust the old stale air. The HRV switches automatically so you don't have to do anything.

In humid climates, you may wish to examine ERV (Energy Recovery Ventilation.) Google tells all you need to know.

HRV systems are expensive. For a large room or a small apartment, you may wish to try a DIY approach. You can make a very effective system for much lower cost. See my first post above.

Reply to
Steve Wilson

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.