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Archive for the ‘micro chp’ Category

a simplified financial model for CHP (or any LZC generation)

Posted in chp, energy, engineering, micro chp, renewable energy on May 14, 2009| 14 Comments »

We engineers are great at estimating energy and carbon emissions and dealing with concrete systems: pipes, wires, flues – that’s our bag. One of the things we do poorly (but for some reason are too willing to do) is financial modeling relating to low and zero carbon generation.

For the last couple of years I’ve been working alongside financial and commercial bods who actually do know what they’re on about and it’s been a real eye opener. They might not know how to size a duct but they can tell you where your business is making money – and where it isn’t.

On a recent project I was looking at small CHP engines (5 – 30kWe) on a sheltered housing scheme. As part of that work, I put together a simplified financial model (with guidance from the bods) to quickly test whether a given option was worth looking at in detail. It was hugely useful and threw up some surprising results – for example, none of the small engines I looked at could pay back its capital cost in its lifetime. Ouch.

So based on that work, here’s the model. I’m using micro-CHP as an example but it’s just as easy to use for renewables.

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more feed-in-tariff changes to Energy Bill

Posted in energy, feed in tariff, micro chp, other stuff, renewable energy, uncategorized, utilities, tagged , on November 16, 2008| Leave a Comment »

There have been further amendments to the Energy Bill in the Lords in connection with feed-in-tariffs. The one year implementation deadline is back in. Excellent news as the detail of how FiTs are implemented will almost inevitably be bogged down in long discussions between government and power suppliers – a one year limit should focus minds.

Also, the 50kW limit on capacity of gas CHP has been lifted. This means (more…)

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gov’t response on renewable heat and feed in tariffs

Posted in biofuel, biomass, climate change, feed in tariff, heat pumps, micro chp, renewable energy, sustainability, wind turbines, tagged , , , , on October 30, 2008| 1 Comment »

Last night, Lord Hunt came back with his amendments to the Energy Bill and, as promised, here’s an update. For electricity feed in tariff, he’s proposed:

  • Feed in tariff for renewable generation up to a maximum of 3MW (excellent).
  • Qualifying technology: biomass, biofuels (oh dear), fuel cells, photovoltaics, water (including waves and tides), wind, solar power, geothermal sources, combined heat and power systems with an electrical capacity of 50 kilowatts or less.
  • No timetable for implementation (as far as I could see – is it buried in there somewhere? What will the Baroness say?)

On a heat incentive:

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feed in tariffs – what just happened?

Posted in chp, climate change, energy, feed in tariff, micro chp, renewable energy, sustainability, wind turbines, tagged , , , on October 23, 2008| 2 Comments »

Away from the fanfare around Ed Miliband’s announcement that a feed in tariff (FiT) is on the way, the Lords have been debating an amendment to the Energy Bill that has the support of Conservatives, Lib Dems, and even some Labour peers.

What’s in the amendment? It says the Secretary of State has one year from the passing of the bill to bring in a feed in tariff. And the qualifying technologies, their maximum capacity, and their level of support are left to the Secretary of State to decide with no specified cap.

Despite wide support, it was clear that the Government wouldn’t officially get behind the bill as it wasn’t their idea. In fact, as recently as June the Government were firmly against a feed in tariff.

Baroness Wilcox, the amendment’s sponsor, has now withdrawn it, but only on the condition that the Government meet specific terms in their own amendment, which they’re expected put forward on 5 November. However, if the Government doesn’t fulfill her demands, she will reintroduce her original amendment. Here are her terms in a nutshell (my comments in italics):

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BERR’s reaction to Citiworks: bad news for small generation in the UK?

Posted in chp, climate change, energy, micro chp, private wire, renewable energy, sustainability, utilities, wind turbines, tagged , , , on June 19, 2008| Leave a Comment »

Yesterday BERR and OFGEM released proposals for changing the way the electricity regulations work with regard to distributed energy generation. This is particularly important because it’s BERR’s first public reaction to the Citiworks ruling by the European Court of Justice two weeks ago.

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emissions from CHP: the standard method is wrong

Posted in chp, climate change, Code for Sustainable Homes, energy, engineering, micro chp, renewable energy, sustainability, utilities, tagged , , , on February 4, 2008| 5 Comments »

[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:

  • 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.
  • These emissions figures can determine whether or not a scheme gets planning permission or passes building regs.
  • 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. (more…)

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without action, the plan for zero carbon homes by 2016 will fail

Posted in architecture, chp, climate change, Code for Sustainable Homes, energy, engineering, micro chp, renewable energy, stamp duty exemption, sustainability, utilities, tagged , , on January 3, 2008| 5 Comments »

The requirement for all homes to be zero carbon by 2016 is going to fail unless we take action now. In particular, a set of interim requirements under the Code for Sustainable Homes must be imposed on private housebuilders. In addition, the Code must allow more flexibility in how zero carbon is achieved.

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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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confused about policy changes? Phil’s crib sheet is the answer

Posted in architecture, biofuel, biomass, chp, climate change, Code for Sustainable Homes, energy, engineering, london, micro chp, other stuff, renewable energy, stamp duty exemption, sustainability on November 22, 2007| 2 Comments »

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.

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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:

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