LPG tank - what am I missing?

[Wagas]

I'm struggling to get a mains gas supply so am looking at alternatives. ASHP seems very expensive at about £10k. I believe Calor sell an LPG underground tank for £1250 + £100 rent per year. What are the downsides? LPG is more expensive than conventional gas but what else am I missing?

 

We don't have a utility room so having a gas combi boiler and no water tank would be attractive to us compared to an ASHP set up.

 

Do regular gas cookers, UFH etc all work with LPG?

 

Just looking for any negatives of LPG from people. Thanks

[Jeremy Harris]

Anything that runs on mains gas can usually be converted to run on LPG OK.

 

Of all fuels available, LPG is probably the most expensive.  I did this fuel cost comparison for our (admittedly very low heating requirement) house a while ago:

 

Quote

Running cost comparison, for a typical year for our underfloor heating with different fuels (costs include standing charge/LPG tank rental, etc) :

 

LPG fired boiler running UFH = £336.49

 

Peak rate electric boiler running UFH = £329.05

 

Oil fired boiler running UFH = £218.91

 

Off peak (E7) electric boiler running UFH = £206.43

 

Mains gas boiler running UFH = £143.76

 

ASHP at peak peak rate running UFH = £102.87

 

ASHP at off-peak (E7) rate running UFH = £89.25

 

Arguably the standing charge for all the electric heating options should be reduced in proportion to the ratio between heating electricity use and non-heating electricity use, as that standing charge will apply irrespective of the heating system used.  I didn't bother to make that adjustment, but it would tend to reduce the cost of the electric heating options by around £40 p.a. or so if I was to do this.

 

[epsilonGreedy]

10 minutes ago, JSHarris said:

Of all fuels available, LPG is probably the most expensive.  I did this fuel cost comparison for our (admittedly very low heating requirement) house a while ago:

 

 

The spread in those fuel costs looks odd, I suspect assumptions made about standing charges create a disparity that would not apply to a typical new build with a larger consumption. Given a new build with a thermal performance half way between building regs and Passiv I assume an ASHP would have to charge up the UFH slab during the day at the standard full KwH electric rate.

 

According to the House Builders Bible, 2017 KwH costs are:

 

Electric Peak 16.0p

Electric @ COP 3 5.3

Mains gas 5.3p

LPG 6.7p

Oil 5.1

 

 

 

[epsilonGreedy]

38 minutes ago, Wagas said:

Just looking for any negatives of LPG from people. Thanks

 

 

Cost of digging a big hole in the garden.

Safety regulations that impose limits on where the tank may be sited.

Barely regulated supplier market with costly contractual lock-in conditions. 

[Conor]

41 minutes ago, Wagas said:

I'm struggling to get a mains gas supply so am looking at alternatives. ASHP seems very expensive at about £10k. I believe Calor sell an LPG underground tank for £1250 + £100 rent per year. What are the downsides? LPG is more expensive than conventional gas but what else am I missing?

 

We don't have a utility room so having a gas combi boiler and no water tank would be attractive to us compared to an ASHP set up.

 

Do regular gas cookers, UFH etc all work with LPG?

 

Just looking for any negatives of LPG from people. Thanks

 

What is your project? New build? Find out what the peak heat demand is, then see what size heating system you need. In our case, it's only 2.8kw, so a 5kw monoblock ASHP will suffice - these cost in the region of £2k.

 

The cost of LPG is only going in one direction, esp as more and more people switch to ASHP and the market becomes less competative and lucrative for lpg.

[Wagas]

24 minutes ago, Conor said:

 

What is your project? New build? Find out what the peak heat demand is, then see what size heating system you need. In our case, it's only 2.8kw, so a 5kw monoblock ASHP will suffice - these cost in the region of £2k.

 

The cost of LPG is only going in one direction, esp as more and more people switch to ASHP and the market becomes less competative and lucrative for lpg.

 

New build. I was told I'd need a 12 kw ASHP and looking online the Samsung for example + tank is £7.5k. Plus the inconvenience of trying to find a place to put the tank (no utility room unfortunately).

[Wagas]

28 minutes ago, epsilonGreedy said:

 

Cost of digging a big hole in the garden.

Safety regulations that impose limits on where the tank may be sited.

Barely regulated supplier market with costly contractual lock-in conditions. 

I'm going to have to big a big hole for a sewage treatment plant so another hole isn't going to make much difference to cost. Plus there's lots of outside space.

[Jeremy Harris]

Currently LPG costs a bit under 7p/kWh. 

 

An LPG condensing boiler will be about 85% efficient on average, so the true cost per kWh will be about 8.2p. 

 

An ASHP will run with an average COP of around 3 (a decent one will do better than this), so for every 1 kWh of electricity used ~3 kWh of heat will be generated.

 

An ASHP running on peak rate electricity, with a unit price of 15p/kWh will deliver around 1 kWh of heat for 5p

 

An ASHP running on off-peak rate electricity, with a unit price of 8.5p/kWh will deliver around 1 kWh of heat for 2.83p

 

Directly comparing just the fuel cost (ignoring the standing charge/tank rental) an ASHP running from E7 off peak electricity will cost about 35% of the cost of providing the same heat from an LPG fired boiler. 

 

The standing charge needs to be accounted for, as the LPG tank rental is an additional annual cost, as the electricity standing charge will need to be paid irrespective of whether electricity is used for heating. 

[SteamyTea]

As there is less than 0.5p/kWh between off peak electricity (does depend on contract) and LPG. Why would anyone bother with LPG.

I think it is just selling an old home heating model that is now superseded.

 

[epsilonGreedy]

5 minutes ago, SteamyTea said:

As there is less than 0.5p/kWh between off peak electricity (does depend on contract) and LPG. Why would anyone bother with LPG.

 

 

I suppose it depends on how cold a house will get in the day when electricity costs much more.

Who wants to cook on an old fashioned electric ring.

How much would a 40Kw instant electric DHW heater cost.

According to this site https://www.confusedaboutenergy.co.uk/index.php/domestic-fuels/fuel-prices off peak electricity is 51% more expensive than LPG.

 

[Jeremy Harris]

23 minutes ago, SteamyTea said:

As there is less than 0.5p/kWh between off peak electricity (does depend on contract) and LPG. Why would anyone bother with LPG.

I think it is just selling an old home heating model that is now superseded.

 

 

Our off-peak rate is cheaper than LPG by a bit, so no real point in paying more for fuel and an additional ~£100/year in tank rental AFAICS. 

[SteamyTea]

9 minutes ago, JSHarris said:

Our off-peak rate is cheaper than LPG by a bit,

Yes, and mine, just.

As I use about 1 kWh/day peak, the rest is off peak, which works out at about 85% of my total usage and considering, in 32 years my maintenance amounts to 1 immersion element (changed cylinder, but that would need changing regardless).

21 minutes ago, epsilonGreedy said:

suppose it depends on how cold a house will get in the day when electricity costs much more.

Any heating system can be designed to cope with any temperature differences, so a bit of an irrelevance there.

If you are still under the impression that even basic storage heaters are useless in all circumstances, then you are very misguided.

[epsilonGreedy]

9 minutes ago, SteamyTea said:

Any heating system can be designed to cope with any temperature differences, so a bit of an irrelevance there.

 

 

I will simplify my point for you. It is misleading to indicate that a house can be heated exclusively from economy rate electricity as your own figures confirm. The further a house thermal performance shifts from Passiv to new build normality then more peak rate electricity will be required.

 

Most normal human beings prefer a house at a toasty 22 degrees at 8pm and a couple of degrees cooler at 4am, E7 heating promotes the converse.

[Jeremy Harris]

Just now, epsilonGreedy said:

 

I will simplify my point for you. It is misleading to indicate that a house can be heated exclusively from economy rate electricity as your own figures confirm. The further a house thermal performance shifts from Passiv to new build normality then more peak rate electricity will be required.

 

Most normal human beings prefer a house at a toasty 22 degrees at 8pm and a couple of degrees cooler at 4am, E7 heating promotes the converse.

 

 

Why?

 

Our first home (not far from where @SteamyTea lives) was a mid-Victorian stone cottage.  it was heated solely by E7, with storage heaters.  Hot water was by a tank heated using E7, too.  The heating and hot water worked just fine, and kept the house nice and warm, even though it had zero insulation.

[epsilonGreedy]

3 minutes ago, JSHarris said:

Why?

 

 

You know why. This is principally a new build forum here homes will vastly exceed the performance of a Victorian terrace. I suppose it is just possible that a leaky old terrace house will shed enough heat when the storage rads are charging at night to maintain a healthy 18 degrees because the vents are closed but because the house is small enough there is enough heat charge remaining to warm a house up at 8pm.

 

With a non Passiv new build the spacing heating electric consumption is going to be closer to 50/50 E7/Standard rate surely.

[SteamyTea]

22 minutes ago, epsilonGreedy said:

as your own figures confirm

What figures?

I think you get kW and kWh confused.

Or, if you prefer your own units

1 hour ago, epsilonGreedy said:

Kw

 

3 hours ago, epsilonGreedy said:

KwH

 

[Carrerahill]

3 hours ago, Wagas said:

I'm struggling to get a mains gas supply so am looking at alternatives. ASHP seems very expensive at about £10k. I believe Calor sell an LPG underground tank for £1250 + £100 rent per year. What are the downsides? LPG is more expensive than conventional gas but what else am I missing?

 

It costs an absolute fortune. If you need tanked fuel go for oil. Issue with gas is you are at the mercy of usually 1 or 2 suppliers and the monopoly they run. I know loads of people who really really hate their off-grid gas supply and the headaches it causes. 

[PeterW]

6 minutes ago, epsilonGreedy said:

With a non Passiv new build the spacing heating electric consumption is going to be closer to 50/50 E7/Standard rate surely.

 

No it’s not.  Storage heaters properly sized will support the heating loads, and it would result in a higher level of storage needed and not peak loading. 

 

The better solution for an older property purely on Electricity for heating may be E10, and use the later period to boost the building temperatures at that point. 

 

 

[scottishjohn]

from my experience changing from LPG to an ASHP --with no other changes to heating system was  a saving  of £1000  a year  

LPG should be your last option

 

[Wagas]

10 minutes ago, scottishjohn said:

from my experience changing from LPG to an ASHP --with no other changes to heating system was  a saving  of £1000  a year  

LPG should be your last option

 

But if ASHP costs £10k more to install than LPG the savings will take 10 years to pay back no?

[PeterW]

Just now, Wagas said:

But if ASHP costs £10k more to install than LPG the savings will take 10 years to pay back no?

 

ASHP shouldn’t cost £10k more though - and you also need to do the whole life cost and include service and install. 

[Jeremy Harris]

27 minutes ago, epsilonGreedy said:

 

You know why. This is principally a new build forum here homes will vastly exceed the performance of a Victorian terrace. I suppose it is just possible that a leaky old terrace house will shed enough heat when the storage rads are charging at night to maintain a healthy 18 degrees because the vents are closed but because the house is small enough there is enough heat charge remaining to warm a house up at 8pm.

 

With a non Passiv new build the spacing heating electric consumption is going to be closer to 50/50 E7/Standard rate surely.

 

What gives you the idea that storage heaters give out lots of heat when charging? 

 

Even 30+ years ago our storage heaters never over-heated the house at night, if anything they didn't really give out a lot of heat when charging at all, as with the damper shut tight most of the heat was retained in the bricks. 

[epsilonGreedy]

15 minutes ago, JSHarris said:

Even 30+ years ago our storage heaters never over-heated the house at night

 

 

Because it was a poorly insulated thermal sieve.

 

There is no overnight damper on UFH so I maintain my point that, in anything less than a passiv house, electric UFH will need substantial top up heating at standard rates. The alternative is a much higher slab temperature target at E7 rates and hence an uncomfortably hot house at 5am. Legions of householders have experienced the inherent problems of E7 storage heating, the issues have been well known for 50 years. New builders considering UFH need to be alert to replicating the same problems with an over dependence on E7 heating cycles. In some respects the problem is exacerbated because a new build will shed less heat and short of throwing down 20 kingsize duvets each night there is no UFH damper option.

[epsilonGreedy]

45 minutes ago, scottishjohn said:

from my experience changing from LPG to an ASHP --with no other changes to heating system was  a saving  of £1000  a year  

LPG should be your last option

 

 

What was your heating bill prior to installing an ASHP?

[epsilonGreedy]

48 minutes ago, Carrerahill said:

I know loads of people who really really hate their off-grid gas supply and the headaches it causes.

 

 

Did these experiences date back to prior regulation of the LPG bulk supply industry?