It's not exactly Greenpeace, concedes the trust's head of technology acceleration, Steve Wyatt, even if it does share the activist group's aim of wanting to limit the effects of climate change.
Wyatt, an engineer, could claim to have the perfect CV for the role of speeding up development and adoption of low-carbon technologies: in a past life his skills were applied to motor racing. He accepts he could be seen as "poacher turned gamekeeper to a certain extent, after all those high-carbon sins of the motorsport industry". Yet, as he describes the trust's history and present activities, his conversion from petrolhead to champion of renewable energy seems convincing.
When the Blair Government set up the trust in 2001, it provided about 95 per cent of its £100 million ($200 million) a year budget.
Britain has a big renewables target. By 2020 the Government wants 15 per cent of its energy - including electricity, heat and transport - to come from renewable sources, up from 1 per cent in 2005.
The target for electricity generation is more than 30 per cent, up from 6 per cent. That will mean mothballing fossil-fuel burning plants like the 1960s era Didcot power station that blights Oxfordshire, and spending billions on wind, wave and other alternative energy sources.
With a Conservative-led coalition now in charge, the trust's funding remains secure although there is a more commercial focus.
"We started out mainly doing energy-efficiency type things. That, I guess, was the low-hanging fruit 10 years ago, helping businesses understand how they could consume less electricity," Wyatt says.
That work branched into carbon-footprinting of products on supermarket shelves, working with the Tesco chain.
"If you walk into a Tesco supermarket here you'll see there are products labelled with a Carbon Trust logo saying, for example, there is 200g of CO2 in this product. We are trying to create an environment where the customer can make intelligent choices about how much carbon they want to consume.
"We began to develop the methodology and standards for that about three years ago and in the past 18 months that's really taken off as something companies are keen to adopt."
The other side of the trust's activities - and where Wyatt's skills come in - is technology development. Unlike working in the pits at a race track, where the aim is to eke fractionally more speed or life out of an engine, in the new world of low-carbon technologies they're still grappling with the fundamentals.
In the marine energy sector, for instance, there's still limited understanding of how to harness waves to generate electricity.
"We still don't understand how to couple with the sea, how to extract energy from the sea in the most efficient way. One of the most beneficial things we can do is just keep increasing our understanding, keep iterating, keep trying to understand how to get more energy yield from wave devices."
And as that knowledge develops, the trust wants to foster creation of a new industry.
"It's a good mix of tangible engineering projects that we're trying to do here and getting the political ducks in a row to create the right environment to make promising technologies happen.
"I guess that's what the Carbon Trust is about - identifying promising technologies and trying to create a political and commercial environment to foster those technologies," Wyatt says.
From its location in the City, it is apparent the trust wants to do its work from within the financial establishment rather than in opposition to it.
"We share this building with lawyers, accountancy firms - it's very much in the heart of the City," says Wyatt, who readily agrees that the trust is a different kind of organisation than Greenpeace, for instance.
"Absolutely right - we took the decision at the outset that if the trust was going to be a success it would be economic factors that would drive it. So we've adopted a very commercial focus.
"We're not a lobby group. We do write publications that set out business cases but we're not afraid to kill things off if it's a green agenda that's not going to work very well.
"But at the same time we stand by our convictions. With offshore wind, for example, we've been very influential in trying to set out government policy and industry policy for what needs to happen."
Conversely, Wyatt says, the trust controversially declared that small wind turbines of about 1m diameter were a dead loss because there was more carbon embodied in their manufacture than they would ever pay back in their lifetime.
Since Britain's May 2010 change of government, the trust's collaboration with the private sector has stepped up a notch. The 95 per cent public funding it received at inception has since fallen to 90 per cent, and the trust's ambition is to reduce it further, Wyatt says.
"In terms of the economic climate in the UK, the Government is under a lot of pressure to get value for money, and one of the ways we can do that is to try to engage with the private sector to get it to fund as much as possible where it makes commercial sense."
Selling carbon-footprinting services is one way the trust can do that. "There's also another example in that whereas historically the government has bankrolled a low-carbon loan scheme for companies wanting to upgrade equipment or change industrial processes, the market is now sophisticated enough for us to use commercial financing products to pay for that."
The trust has a tie-up with Siemens Finance to provide funds for those loans.
"We need to be completely tapped into what the investment community is looking for."
However the private investors whom the trust would like to tap in order to green the energy sector are under the same pressure as the Government.
On a morning in early October, Eurozone anxiety seemed to have already struck as numerous grim-faced denizens of the City headed for work with cellphones clamped to their ears. Although in the thick of the action, the trust is not as buffeted by the markets as the central players are, Wyatt says. In fact a little financial turbulence can be good for the green technologies the trust pushes.
"Rising energy prices, for example, really boost the agenda on the energy-efficiency side of things, and that makes our job easier. If the cost of electricity is going up, people want to do something about the bottom line.
"The flip side is the risk appetite of the market for spending venture capital on innovative technologies is understandably diminished."
Perversely, the resulting scarcity of funds can cause attrition among competing new technologies, making it simpler for investors to judge which are going to be the best bets.
"If you have a raft of wave energy devices, all of different types - and we had that five years ago in the UK - and they all want funding, you don't actually accelerate the industry because you don't know which is the best."
Attrition can lead to design convergence.
"Part of our job is helping financial institutions and the industry understand what is key about a successful technology and teaching them how to identify it. So I spend a lot of time in meetings with VC-type companies educating them around wave and tidal energy, talking to them about what are the important things here, what influences the cost of generation for wave and tidal energy.
"If people can begin to understand the top five questions they need to be asking the technology developers, that makes for a better climate."
If on the one hand the trust's role is courting the money men, it's other is pure engineering. Renewable power generation throws up big challenges, which the trust plays a part in trying to solve.
Offshore wind is seen as a potential source of up to a quarter of Britain's electricity by 2020, by which time there are expected to be several thousand turbines installed as far as 290km from land, some as tall as 200m. They will be producing more than 30 gigawatts of power, about four times New Zealand's present total requirements.
Although Britain is building offshore wind farms as fast as it can - including in the Thames estuary - wind represents something of a lost opportunity, since the technology is being imported.
The next frontier is marine energy, in which Britain wants to be a leader. With funds from the European Union, the Carbon Trust and elsewhere, it has built a test facility, the European Marine Energy Centre (EMEC) in the Orkney Islands.
"We've just done some work that puts the cost of wave energy at 30 to 40 pence a kilowatt hour, depending on location, and 25 pence for tidal," Wyatt says, three or four times the wholesale price of power from a combined gas cycle turbine.
Low-carbon generation gets a leg up from Britain's renewables obligation, effectively a levy on dirty electricity generators. The marine energy sector was celebrating last month when the Government bumped up its share of the subsidy at the expense of the more mature wind sector.
Wyatt says the trust estimates that for 1000 devices producing a gigawatt of electricity, the cost of tidal generation falls to about 13 pence a kilowatt hour, and of wave generation to 14 to 15 pence.
"The trick is knowing what you need to do between now and then to bring down those costs, how do you develop the industry. So a lot of what we do is about setting up innovation projects to develop the right sorts of technologies."
One example is the Scottish-built Pelamis, a snake-like device that generates electricity from hydraulic pressure caused by waves. The Pelamis' evolutionary cycle, which began a decade ago, highlights how backers of new electricity generation technologies need to be in it for the long haul.
In 2008 a first-generation Pelamis was deployed off Portugal and connected to the country's electricity grid, with plans to eventually build a 30-device wave farm.
Around the same time, the design caught the eye of an Auckland investor, Chris Curlett, who put $1 million into investigating the building and installation of a Pelamis wave farm off New Zealand's west coast (see box).
Neither plan came to fruition.
Now, with the help of a £4.8 million grant from the trust, a second-generation Pelamis, the P2, has been developed. One of the 180m-long 750 kilowatt devices has been on trial at EMEC since last year and a second is on its way so they can be tested in tandem.
"It's early days for wave and tidal and the industry itself would say it's still in the proving stage. Before we can press the button and order a thousand of these things and get them out into the ocean, I think we're 10 years away at least."
But Wyatt is confident a greener future lies ahead. "The people who understand the technology are pretty confident it's going to get there."
Coastlines offer huge potential
Britain isn't the only country eager to be a marine energy leader. New Zealand, with thousands of kilometres of coastline, is also a contender.
By one estimate, Cook Strait has the capacity to generate 12GW of power, about one-and-a-half times our present needs. A more conservative official assessment suggests there is national potential of 8GW .
John Huckerby, head of the Aotearoa Wave and Tidal Energy Association (Awatea), says New Zealand has resources to match the much-vaunted potential of Scotland.
"The question is whether you want to be developing technologies in New Zealand to harness those New Zealand resources or do you want to just import the technology," Huckerby says.
He thinks Britain's government-funded Carbon Trust, which researches and helps find investors for renewable energy projects, would be a good model to follow.
So does Chris Curlett, an Auckland investor who spent about $1 million in 2007 on a failed wave energy project. Curlett wanted to build a wave farm using Pelamis devices developed in Scotland and manufactured here.
"We were very impressed with the ability of New Zealand to produce machines but regrettably the financials just didn't work," he says.
He could only look in envy at the government support available to British marine energy pioneers.
That's not to say there is no support for New Zealand ventures. An Energy Efficiency and Conservation Authority (EECA) fund for device deployment has doled out about $4 million to several projects, including one Huckerby is involved with.
Tangaroa Energy, a Whangarei company, is a beneficiary of the fund, receiving about $300,000 in October for a wave energy device to be installed at Stewart Island.
Tangaroa director Kevin McGrath says the EECA funding is a valuable catalyst.
"It's a start, and that's what all of us need to get going."
Britain's efforts to establish a marine energy industry aren't to the exclusion of New Zealand's. McGrath says UK Trade and Investment provided valuable introductions when he attended a renewable energy conference in Scotland two years ago.
Awatea, with the Heavy Engineering Research Association, made a bid in August for the Government to fund creation of a marine energy centre in Wellington.
The centre, which is still awaiting the go-ahead, would provide facilities for testing experimental devices.
According to the Green Party, the global renewable energy market is forecast to be worth up to $800 billion by 2015. A 1 per cent share would result in an industry worth $8 billion and up to 80,000 new jobs.
Anthony Doesburg is an Auckland freelance writer, who visited the Carbon Trust HQ in London
