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Archive for the ‘utilities’ Category

Carbon Trust micro CHP interim report finally out

Posted in chp, climate change, Code for Sustainable Homes, energy, engineering, micro chp, stamp duty exemption, sustainability, utilities, tagged , , on November 27, 2007| 3 Comments »

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.

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SAP and CHP – a dangerous muddle?

Posted in biomass, chp, climate change, Code for Sustainable Homes, energy, engineering, london, micro chp, renewable energy, sustainability, utilities, tagged , , , on November 19, 2007| 6 Comments »

[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:

(more…)

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self-defeating renewables policy

Posted in climate change, energy, engineering, renewable energy, sustainability, utilities on November 2, 2007| 1 Comment »

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.

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CHCP saves carbon? the question is moot.

Posted in chp, climate change, Code for Sustainable Homes, energy, engineering, london, micro chp, sustainability, utilities, tagged , , , , on October 30, 2007| 5 Comments »

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.

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anarchy roundup: CHP and grid emissions

Posted in chp, climate change, energy, engineering, london, micro chp, renewable energy, sustainability, utilities on September 4, 2007| 8 Comments »

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.

(more…)

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micro-CHP report delayed (again)

Posted in chp, climate change, energy, engineering, london, micro chp, utilities on July 2, 2007| Leave a Comment »

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.

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italy vs. uk on microgen funding

Posted in climate change, energy, engineering, italy, renewable energy, utilities on May 11, 2007| 6 Comments »

After I mocked Italy’s efforts to combat climate change, it turns out their funding for microgen (in particular photovoltaic panels) makes the UK’s policy look even more pathetic. If that were possible. (more…)

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spy plane photos shame heat-loss homes

Posted in architecture, climate change, energy, engineering, london, utilities on May 7, 2007| 8 Comments »

A London borough used thermal imaging from the air to help identify properties with high heat loss and they’ve put the results online for anyone to see. Here’s the article in the The Times. And here’s the map showing the results.

I think it’s fantastic, provided the council follow it up with constructive advice to the worst homes and other buildings. Now what we need is a thermal version of Google Earth.

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light bulbs in the priceless supermarket

Posted in climate change, energy, house, italy, utilities on May 3, 2007| 3 Comments »

Found on the back of our electricity bill:

enelbill

When we moved into the house in October of last year there were bare incandescent bulbs hanging from the walls. We didn’t get around to putting in low energy bulbs (CFLs) until December, when we replaced about half. At that point, our average daily electricity consumption dropped 16%. In February we replaced the rest of the incandescents and suddenly we were using 32% less electricity than when we moved in.  (more…)

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