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If you haven’t checked out Michael Willoughby’s biomass blog, Woodfuel Magazine, you should. It’s an RSS feed well worth subscribing to. Keep it up, Michael!
Over on Zero Champion, Phil brought up the subject of payback periods, citing some examples from clients: 12 months, or 18 months, or 39 months.
Those periods equate to ridiculously high rates of return! 100%, 67%, and 31%! Are there so many fabulous investments out there that clients can justify hurdle rates like this?
Could it be that clients are being deliberately obstructive? Or maybe they just want to carry on doing things the way they’ve always done them? By demanding short payback periods they ensure they won’t be lured out of their narrow comfort zone. But this approach is completely unjustifiable.
Ignoring the inherent benefits and taking a purely financial view, a client ought to evaluate low carbon technology in the same way they would look at any other potential investment. Let’s assume our client is a developer with a weighted average cost of capital of 12.5%*. That means they should seriously consider investments that will achieve better than this rate of return. Being conservative, let’s bump it up to 15% - a very attractive investment. We’re still talking nearly 7 years before you’ve recouped your money.
There’s an issue of risk, but only with immature technology. CHP, solar thermal, PV, wind, hydro, biomass heating: these are all tried and tested and, given good site data, their performance can be predicted with a high degree of accuracy. Even with something trickier like biomass gasification, you can factor things like increased downtime into your figures and take a pessimistic view when predicting performance. But that doesn’t mean your hurdle rates suddenly leap into the stratosphere.
So it’s disappointing to hear that client’s are requiring payback periods like 12 months or even 39. They’re taking a distorted view of technology and, in the mean time, promoting the impression that low carbon is somehow so shoddy, so flawed, such a special case, that it should only used if it promises a financial miracle.
* For this example, assume of our developer’s capital, 40% is equity and 60% is debt. Assume cost of debt is 7.5% (LIBOR of 5.5% plus another 2%) and cost of equity is 20%. I’ve ignored tax.
There’s a short video on the Building website of Phil Clark and Michael Willoughby discussing biomass. At one point Michael claims “it’s not efficient to transport biomass more than 20 miles.” Holy smokes, where does this fact come from? I took a stab at the numbers and came up with a figure of 3000km (1900 miles) by truck before you lose the carbon benefit. That’s 100 times more than Michael’s figure. Looks like one of us (or possibly both) has got it wrong.
On a project at Fontenergy we’re looking at some small scale gasifiers that claim to have overcome the traditional problems associated with wood gasification. While doing some research I came across this manual from the Federal Emergency Management Agency in the US, with detailed instructions of how to convert your car, truck, or tractor to run on wood gas in the event of extended petroleum shortages. The practice of using wood gas in internal combustion engines was very common in Europe during the Second World War (apparently 95% of mobile farm machinery in Denmark ran on wood gas - I love Denmark) and this guide is aimed at preserving that knowledge.
I’m taking a sickie, grabbing the tool box and heading for the garage.
Love them or hate them, liquid biofuels are increasingly being put forward as a renewable fuel for CHP. Currently they’re eligible for ROCs and so appear to be considered renewable by BERR and OFGEM.
But when I spoke to the SAP team at BRE, not only did they confirm that liquid biofuels aren’t considered under SAP, they also said that “because of mounting doubts over the extent of emissions from biofuels”, you have to use the emissions factor for oil when carrying out your SAP calcs. Did they expect the treatment of biofuels to change for the 2010 review of SAP? Adamantly, they did not.
Then I called the BREEAM helpline. They told me that liquid biofuels also aren’t considered under the Code for Sustainable Homes. So no help in scoring points under ENE1 or ENE7.
So liquid biofuel CHP is eligible for ROCs but will do little for your Part L and Code requirements. Without achieving these requirements, the case for biofuel CHP for new buildings is severely undermined. Obviously this situation could change. With CLG on the lookout for ways to meet the 2016 zero carbon homes target, there might be considerable pressure applied in favour of making biofuel renewable under SAP. But for now the official line is that biofuels are not a solution for carbon reduction in new build.
The UKGBC is launching plans for a Code for Sustainable Buildings to “address the confusion arising from the myriad of different green building standards.” Although they’ve used the name, this isn’t the same Code for Sustainable Buildings that we were promised a few years back and that was eventually pared down into the Code for Sustainable Homes. This is an “open-source” UKGBC-managed standard which could then be used in other standards.
Reading between the lines, the UKGBC have just pre-empted a situation in which BREEAM is adopted wholesale as the basis of a future Code for non-residential buildings (a situation like we saw with EcoHomes and the CfSH). It looks to me like they’re looking to usurp BRE’s place as guardian’s of the public interest when it comes to building performance and I suspect the use of the words “open-source” is a stinging reference to BRE’s increasingly mercenary approach. So take that BRE - you’ve just been King-slapped.
Or am I just looking for drama on an otherwise dull Tuesday?
For a while, I have suspected that the thermal efficiency requirements for Code 6 would almost certainly require MVHR. But I was always dimly aware that I hadn’t actually done the numbers and so couldn’t be sure. Now I am: no MVHR means no Code 6.
If you build to Passivhaus standard, there’s no point in putting in a wet heating system. In fact, the key to the economics of Passivhaus design is that a conventional heating system is rendered redundant: you’re supposed to use the resulting savings to help fund the efficiency measures. Instead of a boiler and radiators you might only need a small electric heating coil in your mechanical ventilation system.
Level 6 of the Code for Sustainable Homes is modelled on the Passivhaus standard. As a result, until the Code changes, you’re likely to see more and more developers trying to move towards electric heating systems. You might argue that given the quantities of electricity we’re talking about (15 kWh/m2.yr), even if you source the electricity from the grid, it’s no carbon catastrophe. Unless you consider the bigger picture.
Making new buildings zero carbon is an excellent requirement, but by focusing our efforts (and a hell of a lot of money) on ratcheting down the heat demand from new buildings, we throw away the huge opportunity of using new developments to slash emissions from existing stock. Read the rest of this entry »
At work I’m helping a large housing association upgrade their existing heating networks to save carbon and reduce costs to occupants. There are various steps to take: upgrading boilers, re-insulating distribution pipework, considering CHP, and so on. But the single most effective thing you can do on these schemes is to install heat meters.
Doing some background research, I rang up the very friendly and forthcoming Dick Bradford, the driving force behind the hugely successful biomass community heating schemes in Barnsley, to ask him what effect installing heat meters had had on his schemes. He told me that following the installation of heat meters, heat consumption dropped by 50%. I was gobsmacked.
My first day back in London and I’ve spent the morning schmoozing at a publication launch just off the Mall. Five minutes out of my cattle stall and I’m already moving and shaking. It was an event to publicise the TCPA’s new document, Community Energy: Urban Planning for a Low Carbon Future, and it attracted quite a crowd including MPs Nick Hurd and Keith Hill.
During the presentations and panel discussion, most people in the room seemed to feel that local authorities have the pivotal role to play in the creation of low carbon distributed energy networks. I totally agree, but I think we were missing part of the picture.
I’ve been spending some quality time with spreadsheets and have an update on the way building regs for housing treats CHP. It’s not as simple as I thought here, although the result is similar. The incorrect method I wrote about a few weeks back is still in use, but it’s different from what’s happening in SAP 2005. Here’s a breakdown:
Martin at isite has got in touch to urge us to wear blue on Earth Day (April 20th) to signify opposition to new coal.
We’re with you, Martin. Time to break out the body paint.
Today Lord Turner’s panel met for the first time to discuss a concrete strategy for fufilling the UK’s commitment to reducing emissions by 60% by 2050 (and to consider upping the target to 80%). With around a third of UK emissions coming from housing, this sector will inevitably play a key role in their strategy. You might think we could rely on the Code for Sustainable Homes to get us there - after all, if all homes from 2016 are Code level 6 then there will be no net emissions from new housing. But unfortunately new homes are only a small part of the problem.
The graph below illustrates the predicted emissions from the housing sector by age of housing stock for the period 2002 to 2050. It shows that the overwhelming proportion of emissions will continue to come from houses built before 2002. The dotted lines represent the emissions from all housing required to achieve a 60% and 80% reduction in emissions vs 1990 levels. Emissions from each band decreases over time due to demolition.
Figure 1. Carbon emissions from housing sector by age of housing stock, 2002 - 2050
Greenpeace has created their version of a model town, stitching together examples from all over the UK. It’s a very cool combination of flash pages with lots of case studies, animations, and videos. Worth a wander.
At first glance, the green credentials of ground source heat pumps (GSHPs) look unquestionable: because you’re harvesting free heat from the ground, you can get up to four times more energy out of the system than you put into it. Sure, it runs on electricity, which is more carbon intensive than gas, but because of this favourable ratio of output-to-input (called the COP for coefficient of performance) the system should still emit less carbon than a gas boiler - in theory.
But the claimed benefits are reliant on incorrect assumptions. A new house will emit about the same carbon using a ground source heat pump as with a new gas boiler. Here’s why:
[update March 20: I've looked further into how SAP treats CHP and written it up here. So while the method described below is being used elsewhere in the industry, the criticism doesn't apply to SAP.]
I’ve written on this topic before but maybe I didn’t succeed in making clear just how far off the mark the standard method is when estimating carbon emissions from CHP. Why does it matter? Here are some reasons:
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Right now, big developers and the Housing Corp are assuming CHP can get them to level 4 under the Code for Sustainable Homes and this may not be true.
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These emissions figures can determine whether or not a scheme gets planning permission or passes building regs.
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The nascent micro-CHP industry (expected to be worth £2billion per year across Europe) is using this flawed method to back up its sustainability claims. Changing from a commonsense approach to the much more forgiving “standard” approach explains why the first Carbon Trust interim report on the micro-CHP field trails was so bleak and the second was so rosy.
There’s a good chance that, if I’m right and the standard approach is flawed, when the CLG and BRE realise their mistake, the rules will change, leaving public and private sector developers and the micro-CHP industry with a very costly mess to clean up. Read the rest of this entry »
If the government backs up Medway Council’s inane decision to allow a new coal fired power station in Kent, I’m going to pack it in. The superfluous runway at Heathrow is bad enough, but new coal? The squabbling we all do over saving a tonne of CO2 here and a tonne of CO2 there - and Gordon Brown is going to give us the first new coal plant in 30 years?
Seriously, I’m going to put my feet up, club a baby seal, hit the hash pipe, and join the national guard. Who knows, I might even become the next prime minister.
Much later than planned, but here it is. In summary, micro-CHP saves 5% to 10% of carbon in large inefficient houses but only if you use a flawed methodology and give yourself extra-extra credit for displacing grid electricity. A few of the key findings:
- The trial has demonstrated that the carbon and cost savings from Micro-CHP are generally better for buildings where they can operate for long and consistent heating periods.
- In small commercial applications, the field trial has shown that Micro-CHP systems can provide typical carbon savings of 15% to 20% when installed as the lead boiler in appropriate environments.
- The domestic Micro-CHP systems monitored in the trial have the potential to provide typical carbon savings of 5% to 10% for older, larger houses with high and consistent heat demands (over 20,000kWh/yr).
So since the last report, the Carbon Trust has toed the industry line that the 0.568 figure should be used.
There’s some very interesting output from the boiler field trials in the report as well. In particular, the boilers they’re monitoring are generally performing 4% to 5% below their SEDBUK rating.
Phil Clark and Fulcrum have put together a fantastic list of upcoming proposed policy changes relevant to construction. Though I couldn’t find the attached doc he talks about: Fulcrum’s housing chart - where is it? Phil’s promised to keep the list updated as more information is released.
That’s just saved me a pile of research this morning, Phil. Thanks.
[Update March 20 - while it's true that SAP gives misleadingly high emissions savings for CHP, I got the methodology wrong. See an updated post here. Points 3 and 4 below are still valid.]
The SAP results for dwellings using CHP are badly skewed. This may cause large developers to formulate strategies for meeting the Code for Sustainable Homes which fall well short of the targets.
Doing some research this week, I read the Housing Corporation’s report on the estimated costs of meeting various levels of the Code for Sustainable Homes. It’s an interesting document, but at a certain point I was confused by their claim that you can meet the carbon reductions required by code level 4 (i.e. a 44% reduction in DER relative to TER) just by using gas CHP. In fact, when I looked closer I found that in some cases, they were claiming an emissions reduction of over 50% - an extremely high figure. Something closer to 10 and 15% is much more reasonable, unless you want to get Orchardesque.
The source of these wild claims is the Government’s Standard Assessment Procedure for dwellings - SAP 2005. As hinted at in the CHP debate running in the BSJ over the summer, SAP does some funny things when it comes to CHP. Have a closer look at the SAP worksheets and you find that SAP:
Rather than taking action to meet its commitments on renewable energy, Brown’s government is actively wriggling out of them. Even more pathetically, it’s trying to persuade other governments to soften their line, let the targets slide a bit, don’t worry so much about climate change. Why? Because in the view of Brown’s advisers (in which we might include the CBI), the targets just aren’t realistic. We’ve done all we can and it just won’t work.
Over a year ago, the Carbon Trust were sending up warning signals about the inefficiency of the Renewables Obligation (RO), the Government’s primary method for supporting renewable energy technology. They found that the RO is the worst of all possible options. Yep, of the methods they considered, the RO is the least practical and cost effective method of achieving renewables targets and carbon reduction. And the best? Feed in tariffs similar to those that sparked the PV boom in Germany and that you find in Italy, Spain, Greece, and other countries.
So why does the UK stick to a doomed policy? Probably a number of things: Government inertia, the nuclear lobby feverishly presenting themselves as a silver bullet, utilities hoping to maintain current margins. But little in the way of valid argument. There’s no excuse for shirking responsibility on this issue.
Over the summer there was a debate between some big names in engineering over whether combined heat, cooling, and power (CHCP) using absorption chillers actually saves carbon. The theory goes that because engine size is usually dictated by the base summer heat load, the additional heat load from the chillers allows you to upsize your engine and generate more low-carbon electricity throughout the year.
However on a current project, we’re looking at the feasibility of installing a district heating and cooling network, including installation costs. And one thing is clear: regardless of whether CHCP saves carbon, the capital cost of cooling is unaffordable.
Back in the UK for project meetings, I arrived at my inlaws’ house in Dorking yesterday evening and within minutes my father-in-law was spreading the Telegraph on the table, pointing to the article about how long efficiency measures take to pay back. Phil at the Sustainability Blog has already commented on the RICS claims and I agree with him.
And here’s first hand proof of the damage their histrionics have done: as I explained to my father-in-law that the RICS study was making unreasonable assumptions (e.g. simple payback calculations) his eyes glazed over. Why? Because the soundbite had already done its job. Nevermind the VAT debate or discussion of EPCs, he’s now more convinced than ever that there’s no point in pursuing any of this eco-treehugging-mumbo-jumbo as it’s obviously frivolous and expensive.
Thanks RICS.
I’m doing financial comparisons of energy systems on one of our projects. It’s a pretty standard part of our work but this morning the precision of the figures appearing in my spreadsheet strikes me as particularly specious because it doesn’t tell the whole story. Sure, clients need a comparator and you can’t preface every report with a thesis on complexities of the energy market (not that I’m capable) but just the same these results are making me uneasy and here’s a short list of reasons why:
A project I’ve been involved in at XCO2 won the Building Design /100% Detail Cool Wall contest last Sunday. It’s Far End House, set to be the first PassivHaus in the UK (fingers crossed). My involvement has been limited to working through the PHPP spreadsheets - Jayde Austin has done all the hard work - but I wanted to shout about it anyway.
In this case, mob justice was right.
David Orr’s comments at the NHF annual conference last Friday have sparked off a row with the Homes Builders’ Federation. In response to Orr’s suggestion that developers won’t hit the governments target of all new homes being carbon neutral by 2016, head of the HBF Stewart Baseley said oh yes we will.
But given that it appears the Treasury is trying to make it much harder (and more expensive) to officially go carbon neutral, it’s likely that developers will have to pay up or change their tune before long. Maybe to one of the old protest songs - We shall overcome perhaps?
In Building yesterday, a study by London South Bank University says a quarter of schemes in London are exceeding the 10% target. The article states:
In total the study, undertaken by London South Bank University, looked at 113 detailed energy statements for schemes that had been given planning approval.
Erm, but none of those scheme has been built yet. And currently there’s no mechanism for enforcing adherence to the commitment by developers - unless it’s written into a Section 106. This enforcement mechanism is a tricky issue that hasn’t been resolved as far as I know. The study also finds that:
…the most effective technologies at cutting carbon are CHP and CCHP, particularly where biomass fuel is used.
Fantastic, and I’m looking forward to seeing more biomass in London. We’ve specced it on a number of jobs, the first of which is up and running. But I can say that using biomass heating (never mind biomass CCHP) brings its own logistical tangles. It’s one thing to tot it up on a spreadsheet and another entirely to bring to fruition.
Without succumbing to the pessimism that seems de rigeur when blogging about the government’s or the GLA’s green policies, I’d just like to add a note of caution. The schemes have been granted planning permission but are by no means home and dry. A follow up survey is needed to see what’s actually built.
(Spotted by Mel at Elemental) Cyril Sweett have published their research into the potential for improving energy performance of existing building stock. The importance of greening existing buildings is brought home by two facts:
- 44% of all CO2 emissions in the UK comes from energy use in buildings
- According to one of the report’s authors, in 2050 60% of Britain’s buildings will still pre-date the 2006 revisions to Part L
So we can look forward to the carbon reductions required by Part L being ratcheted up in future, but the overall effect will be modest, even in the long term. If we want to save carbon NOW then energy consumption in existing buildings is too important to ignore.
Predictably, the report’s top recommendation is for “brave decisions” by the government. But in a political climate where politicians would rather engage in creative accounting than be decisive on climate change, it’s hard to be hopeful.
What’s going on?
There’s been a fierce debate among energy bods this summer over the environmental effectiveness of combined heat and power (CHP) and CHP with cooling (CCHP) – a debate closely tied to assumptions about the carbon emissions associated with grid electricity in the UK.
What happened?
As noted in this blog in May, Arup associate director James Thonger opened up with a broadside aimed at the GLA policy of requiring CHP and CCHP on new developments. In particular he refuted LCCA claims that gas CHP saves 54% of carbon relative to grid electricity. The LCCA is headed up by Allan Jones, former green god of Woking and now darling of the London Mayor, who didn’t take the criticism lightly.
Following our recent blog conversation about the energy consumption of Portcullis House, Phil at the Sustainability Blog has pointed out the recently published consumption figures for another Hopkins scheme - this time the Gibbs Building owned by the Wellcome Trust. Like Portcullis House, it’s an office building kitted out with plenty of green gear. And like its cousin, the Gibbs Building is consuming more energy than predicted at design stage. So is the green office building just a myth?
An article in the Times over the weekend claims that walking to the shops emits more CO2 than driving. It’s a sensationalist claim (even if they can back it up with calcs) that doesn’t help anyone except Daily Mail readers desperate to shore up their view that anyone who thinks about energy or the environment is a commie pinko control freak determined to spoil everyone’s fun. Chris Goodall, the man behind the claim, should have known better and is clearly more interested in headlines than making a genuine difference.
Every little helps. But all things being equal, the fight to alleviate the effects of global warming isn’t going to be won between your house and the shops. It’s much more useful to keep your eye on the crucial issues rather than handing ammunition to the folks who like nothing better than a bit of obfuscation.
Via zerochampion, the Guardian’s architecture commentator suggests that buildings
…should only really be offered prizes 20 years after their completion. While we can comment on the merit of the design, look and feel of a particular building when new, and celebrate the intentions of its designers, there is no guarantee that it might not prove to be a failure.
I know we ought to be happy that architecture is being discussed on TV at all. Having said that, if I were in charge of the Stirling Prize I’d consider actual measured energy use and give occupants a vote on whether they think the building is a success.
Client (on seeing the staircase dominating his hall): But I didn’t want a black marble staircase, I wanted an oak one!
Lutyens: What a pity.
This is driving me nuts. There’s now a huge emphasis on sustainability in architecture but some architects still don’t get it. Aflame with good intentions at the start of projects, they enthusiastically buy into sustainability concepts. But later in the design when there’s a perceived conflict between the energy performance and the architecture, the energy performance is chucked out the window.
Mechanical ventilation with heat recovery (MVHR) is often put forward as part of a low-energy design strategy for homes. The principle is that you build your house air-tight to minimise air infiltration and then mechanically supply fresh air via a heat exchanger. This heat exchanger captures the heat energy in the warm outgoing air and transfers it to the fresh incoming air. Some MVHR units can reclaim as much as 90% of outgoing heat, potentially making drastic cuts to your heating load while maintaining high internal air quality (that’s the theory). All of this is part of the build tight, ventilate right strategy that you hear so much about.
But how air-tight do you have to build before MVHR makes sense? I took a look using SAP 2005, and here are the results:
Next year we reach a milestone unprecedented in history when more than half of all people will live in cities. This comes from the UN’s new State of the World Population report, which strikes an interesting tone. The authors acknowledge the huge risks of increasing rates of urbanisation, particularly for the poor, but also maintain that if we get our urban planning and public administration right, we can design out the worst of our environmental and social problems. And anyway, urbanisation is inevitable because you can’t have economic growth without it.
You could argue that here in the developed world, we’ve got enough urban planning experience under our belts to allow us to meet the challenge. Except that the developed world is not where the real expansion is set to take place. Most of the shift will occur in Asia and Africa where “the accumulated urban growth of these two regions during the whole span of history will be duplicated in a single generation.” So to describe the pace of expansion as breakneck is putting it mildly.
Just heard from the folks at the Carbon Trust who are doing the micro-CHP field trials. The release date for the next interim report has been pushed back to the end of August with the methodology to follow some time after. Advise not holding breath.
Phil Clark at Zero Champion sent a request under the Freedom of Information Act for figures on CO2 emissions for Portcullis House, the office building for Members of Parliament across the road from Big Ben. When he received a response he wasn’t sure if performance was good or bad. It’s bad:
There was an article in the Guardian last Saturday (thanks to Tessa for spotting it) by Alex James, the bassist from Blur, about having an architect come to his home to give green advice. It’s a scheme run by the RIBA where architects provide green advice in exchange for a donation to charity. At first glance this sounds positive. Certainly it’s a great channel to spread information on energy efficiency.
But things get a little weird when the article states that thick rubble walls keep the house warm in winter - which they don’t. Then architect George Stowell suggests that Alex installs a biomass CHP unit to generate his own electricity on site from wood chips. But there aren’t any commercially available biomass CHP units on a single house scale (or even twenty times that big). He may have meant biomass heating, but it’s a hell of a mistake to make, recommending something that doesn’t exist.
It might be better to send a services engineer. CIBSE should consider something similar to the RIBA programme.
A project I led at XCO2 is being featured in the Ecotech supplement in Architecture Today this month (no link yet). It’s a visitors centre for the National Trust in the Chiltern Downs expected to provide services to around 400,000 visitors a year. And it’s loaded with green goodness: woodchip boiler for space and water heating, rainwater harvesting for toilet flushing, and an earth coupled ventilation system that brings air into the building through a 90m long concrete pipe buried below ground. Read the rest of this entry »