Green Building Forum - Biomass heating

Biomass heating

WillInAberdeen — Sun, 13 Aug 2023 15:27:14 +0100

https://www.gov.uk/government/publications/biomass-strategy

Government just published the "UK Biomass Strategy"

Seems pretty opposed to biomass heating for houses:

- HVO should be directed towards aviation (rather than heating or road fuel)

- Woody fuel/pellets should be directed towards biomass power stations with CCS, to reduce unsustainable imports

Possible exceptions for a few rural properties, but heatpumps preferred.

Biomass heating

Artiglio — Sun, 13 Aug 2023 17:52:34 +0100

Not looked at the link beyond seeing its 200 pages long, but given that less than 10 years ago the gov was actively encouraging people to install biomass in homes off the gas grid via the rhi scheme, is there going to be a similar scheme for those now effectively abandoned as the reisdential biomass â€œindustryâ€ effectively disappears, it pretty much already has. Biomass systems being pulled out and replaced at considerable cost with the oil/ gas they originally replaced. An utter disaster in policy terms.

Biomass heating

Peter_in_Hungary — Sun, 13 Aug 2023 19:23:23 +0100

So biomass follows the same route as diesel cars - the end of which is to penalise those who followed the advice then given by those doing todays penalising.

Biomass heating

cjard — Mon, 14 Aug 2023 08:47:59 +0100

I do wish they would just make note somewhere they won't forget: "burning stuff is antisocial"

Biomass heating

Jeff B — Mon, 14 Aug 2023 10:41:18 +0100

Posted By: ArtiglioNot looked at the link beyond seeing its 200 pages long, but given that less than 10 years ago the gov was actively encouraging people to install biomass in homes off the gas grid via the rhi scheme, is there going to be a similar scheme for those now effectively abandoned as the reisdential biomass â€œindustryâ€ effectively disappears, it pretty much already has. Biomass systems being pulled out and replaced at considerable cost with the oil/ gas they originally replaced. An utter disaster in policy terms.

I was one of those people and yes, I have gone back to oil at considerable cost! Actually we were pioneers in this area in that we installed our first wood pellet boiler before the RHI scheme came into existence. I guess we were lulled into it by believing that these pellets would be manufactured using waste sawdust rather than from trees grown specifically for that purpose.

I haven't got the time or the enthusiasm to read the 204 page report but I did read the executive summary and found this section:

"Biomass will likely have a role in heating in certain properties such as off-gas grid homes that are not readily suitable for heat pumps, and where appropriate mitigations can be set in place to minimise air quality
impacts. The government is considering a range of options to decarbonise these".

Not quite sure what the last sentence means?

Biomass heating

revor — Mon, 14 Aug 2023 10:57:00 +0100

I discounted pellet boilers when we were doing our build and refurb. A builders merchant I visited a lot during our period of activity had a pellet boiler and each time I visited it seemed there was an engineer fixing it. That was part of our decision to avoid such boiler plus the comments on this forum of maintenance issues. I was in there a couple of weeks ago and it had been removed. I was told they had so much trouble with it so the plan was fit something else.

Biomass heating

Fred56 — Mon, 14 Aug 2023 11:57:48 +0100

Posted By: Jeff B
Posted By: ArtiglioNot looked at the link beyond seeing its 200 pages long, but given that less than 10 years ago the gov was actively encouraging people to install biomass in homes off the gas grid via the rhi scheme, is there going to be a similar scheme for those now effectively abandoned as the reisdential biomass â€œindustryâ€ effectively disappears, it pretty much already has. Biomass systems being pulled out and replaced at considerable cost with the oil/ gas they originally replaced. An utter disaster in policy terms.

I was one of those people and yes, I have gone back to oil at considerable cost! Actually we were pioneers in this area in that we installed our first wood pellet boiler before the RHI scheme came into existence. I guess we were lulled into it by believing that these pellets would be manufactured using waste sawdust rather than from trees grown specifically for that purpose.

I haven't got the time or the enthusiasm to read the 204 page report but I did read the executive summary and found this section:

"Biomass will likely have a role in heating in certain properties such as off-gas grid homes that are not readily suitable for heat pumps, and where appropriate mitigations can be set in place to minimise air quality
impacts. The government is considering a range of options to decarbonise these".

Not quite sure what the last sentence means?

It also says;
We are not considering a ban on domestic
burning in England. The UK government
recognises that some households are reliant
on solid fuel burning as a primary source for
heating, hot water, and cooking. With this
in mind government is not seeking to ban
burning. This is particularly pertinent in light
of the current focus on energy security and
the global rise in energy prices.

However, it points out in an earlier para words to the effect that councils have the power to set their own clean air standards. I suppose that means that some council may decide to eliminate biomass burning in their areas by default by setting tight air quality standards. Seems fair to me if that's what the local population want.

Personally, I don't think we should be burning anything but I am challenged when it comes to older rural homes that are hard to heat and impossible to bring to a reasonable standard of fabric energy efficiency.

That Eustice chap must have been warned that this was coming. He was gobbing off about a week or so ago pushing for HVO to be encouraged for use in oil boilers as a kerosene replacement. Now that has been squashed it seems he got his rearguard up in advance to deflect criticism from his rural constituents.

I currently have oil heating in a 1970s bungalow and HVO may have been an interesting stepping stone whilst the boiler works out it natural life. I would have needed a guarantee that the HVO contained no palm oil.

Biomass heating

Fred56 — Mon, 14 Aug 2023 12:00:13 +0100

Oh, I should have said,

Thanks WillnAberdeen for your summary. I admire your fortitude. That document if just full of opaque waffle and it is truly boring.

Biomass heating

gustyturbine — Mon, 14 Aug 2023 13:29:19 +0100

I also considered Biomass when we built some 11-12 years ago. I can remember discussing it on here with Jeff B. Luckily as I didn't room for pellet storage I went for a bore holed GSHP. TBH it's been great and the RHI was a real help for the first 7 years. Having said that I do use a lot of power and I wander if financially oil would have been cheaper. I just couldn't do that though being in the renewable industry. I think though as I'm building again I'd go solar PV with ASHP. I'd like 10kW of PV ground mounted but I have no export capacity above 3.68kW.

Biomass heating

revor — Mon, 14 Aug 2023 17:22:23 +0100

Posted By: gustyturbineI'd like 10kW of PV ground mounted but I have no export capacity above 3.68kW.

Stick it in a battery. In there it is worth 30p a unit when you come to use it, export, lucky if you get 10p. If you are using a lot of power you will use your 10kW anyway.

Biomass heating

djh — Mon, 14 Aug 2023 17:28:59 +0100

Posted By: gustyturbineI think though as I'm building again I'd go solar PV with ASHP.

That can work in terms of net zero averaged over a year but it's not well matched to the actual demand. And a battery doesn't really help with that. An offsite wind turbine seems like the best option to me at present, given the potential hassles of having one onsite. Maybe if/when there is commercial tidal generation it will be possible to buy a stake in that?

Biomass heating

philedge — Mon, 14 Aug 2023 21:34:54 +0100

Posted By: gustyturbineI'd like 10kW of PV ground mounted but I have no export capacity above 3.68kW.

So youll have up to 10kW to use within your house with an export limitation scheme to keep export below 3.68kw. That should be able to power a fair chunk of ASHP daytime demand.

Biomass heating

GreenPaddy — Tue, 15 Aug 2023 08:29:09 +0100

Just chucking a few numbers at the 10kW PV winter usage:

I'm a fairly average Joe, with 2 adults and 2 kids in a 220m2 total floor area house. NO ELECT used for heating or DHW, so easy to split out elect usages. My actual recorded usage/gen (data for last 10 years) as follows...

- in December, I usually get about 25kWh over the month from a 4kWp PV system (worst month)
- ave for Jan/Feb is about 50kWh per month
- my consumption av about 350kWh per month for each of Dec/Jan Feb

- for 10kWp system lets say gen 65kWh Dec and 125kWh Jan/Feb each month (mult by 2.5)
- not even beginning to cover the 3 worst winter months NON heating power demands

- by March, with a 10kWp PV my gen would approx = import (slightly later, as import is reduced due to PV home consumption)
- by Nov would have returned to gen approx = import

That says to me, (if I've not screwed up my sums), that from Nov to Mar, I would not contribute from a 10kWp Solar PV to run my ASHP, and that's assuming I had batteries to make use of all the PV I gen.

Since Nov-Mar is the heating season, even with 10kWp PV, solar does not have any bearing upon the heating system.

HOWEVER, with batteries, the opportunity for cheap import and storage makes heat pumps excellent heat energy solutions for homes during the heating season, IF you have a heat energy demand large enough to make the capital investment, and annual maintenance charges for HP's worth while.

My point is NOT to poo-poo HP's or solar, but that consumers need to be clear about what deliverables they will get from a chosen system. Often sales blurb generalises, and the desire to be GREEN, guide people down an expensive and poorly rewarding (money & carbon) route.

Biomass heating

tony — Tue, 15 Aug 2023 11:03:51 +0100

Nice analysis, thanks.

Biomass heating

djh — Tue, 15 Aug 2023 17:50:32 +0100

Posted By: GreenPaddy- in December, I usually get about 25kWh over the month from a 4kWp PV system (worst month)
- ave for Jan/Feb is about 50kWh per month
- my consumption av about 350kWh per month for each of Dec/Jan Feb

Interesting figures, and significantly different from mine. I don't keep monthly averages, although I could work them out if necessary, but just looking at Dec 21 et seq, I see
- Dec 21 = 49.6 kWh
- Jan 22 = 99.2 kWh
- Feb 22 = 182.0 kWh
Dec 21 was my worst month to date, and the other two months are typical. I too have a 4 kWp system, limited to 3.68 kWp. I suppose location accounts for most of the difference, though I guess technology differences might have some impact too.

HOWEVER, with batteries, the opportunity for cheap import and storage makes heat pumps excellent heat energy solutions for homes during the heating season, IF you have a heat energy demand large enough to make the capital investment, and annual maintenance charges for HP's worth while.

I think there's one assessment for heat pumps and then a separate one for batteries. We use direct electric heating so I keep reconsidering whether a heat pump is worthwhile either economically or on the carbon front. But we normally do all our heating overnight so there's no advantage to storing electricity. We can just store the heat.

Biomass heating

revor — Tue, 15 Aug 2023 19:39:47 +0100

Posted By: djhI too have a 4 kWp system, limited to 3.68 kWp.

Do you mean that most you can produce is 3.68 or can you generate 4kw and the 3.68 is the export cap?
Not looked at my figures but prompted by this post. Our system is 6Kwp but have adjusted down as if was 4 kwp
Nov 22 102
Dec 22 81
Jan 23 99
Feb 23 159

Biomass heating

djh — Tue, 15 Aug 2023 20:31:38 +0100

Posted By: revorDo you mean that most you can produce is 3.68 or can you generate 4kw and the 3.68 is the export cap?

The former; although it would be nice to have the latter I have no technology able to measure the export accurately, let alone control it.

Biomass heating

revor — Wed, 16 Aug 2023 19:48:41 +0100

Posted By: djhThe former; although it would be nice to have the latter I have no technology able to measure the export accurately, let alone control it.

Do you get FIT what you generate must be measured to get payment for 50%

Biomass heating

djh — Wed, 16 Aug 2023 20:48:13 +0100

Posted By: revor
Posted By: djhThe former; although it would be nice to have the latter I have no technology able to measure the export accurately, let alone control it.

Do you get FIT what you generate must be measured to get payment for 50%

Correct, yes. Was there a point?

Biomass heating

revor — Thu, 17 Aug 2023 14:02:27 +0100

Posted By: djhCorrect, yes. Was there a point?

The point being it must be measured accurately i,e what you generate, so you get the 50% FIT. So how is that metered. Why do you need the export measured accurately.
If you have a SMETS 2 you could have it accurately metered and get an export payment in addition to your FIT.
I do not understand why you are not generating the full capability of the panels is it to do with the micro inverters. Is there a clamp somewhere on your tails that controls the export limit. A conventional string inverter will not limit the total output just restrict what goes to the grid.

Biomass heating

djh — Thu, 17 Aug 2023 17:04:38 +0100

Posted By: revorThe point being it must be measured accurately i,e what you generate, so you get the 50% FIT. So how is that metered. Why do you need the export measured accurately.

As you state, I must have an accurate generation meter in order to be paid for FIT with deemed export. Equally I clearly do not have either an accurate export meter or a smart meter since I have already stated that I have no means to accurately measure export. I would need an accurate measure of the export if I was to have a system that was capable of dynamically limiting the export to 3.68 kW rather than having a static generation limit as I do. I thought that was obvious.

I do not understand why you are not generating the full capability of the panels is it to do with the micro inverters. Is there a clamp somewhere on your tails that controls the export limit. A conventional string inverter will not limit the total output just restrict what goes to the grid.

Yes I have microinverters and yes somehow they limit the generation. There is no way either they or a conventional string inverter could limit export since they have no means to measure it. I do have various CT clamps on the system as part of my OEM logging system, but they are not revenue grade and are not connected to the generation system or associated with it in any way.

Biomass heating

revor — Thu, 17 Aug 2023 19:00:00 +0100

Is the issue common to all systems with microinverters or could you upgrade to a more favourable install that solves the export measurement and control? A SMETS2 would solve the measurement but not the control. I was very reluctant to have a smart meter but had to have one in order to get export payment as FIT had finished. It is accurate I have another meter which controls the inverter and they both agree.

Biomass heating

djh — Thu, 17 Aug 2023 20:12:22 +0100

Posted By: revorIs the issue common to all systems with microinverters or could you upgrade to a more favourable install that solves the export measurement and control?

I have no idea about other microinverter systems or indeed other 'regular' inverter systems. I don't believe that Enphase offer a suitable 'upgrade' to my system. But I don't have a problem with my system that inclines me to seek a change anyway.