Feeds:
Posts
Comments

Archive for the ‘engineering’ Category

sadly, another nail in the coffin for small wind

Posted in energy, engineering, renewable energy, wind turbines, tagged , , , on January 14, 2009| 3 Comments »

According to the Guardian, most domestic turbines are only generating 5-10% of the manufacturers’ claims. Dramatic stuff but maybe not a huge surprise. I think there’s been a growing realisation among professionals in the built environment that small wind in built up areas rarely works.

But it’s important to remember that in most cases this poor performance is not the fault of the turbines themselves; they’ve just been placed badly by designers and over-hyped by manufacturers.

Located somewhere with decent wind (on the back of a sailboat, on top of a tall mast on a windy hill, etc) they’ll do the job. But bolted to the chimney of a Victorian semi in Surbiton? Almost definitely not. Even Ashenden House, a 13-storey tower in Elephant and Castle, hasn’t proved to be a salubrious place for turbines.

So blame the engineers and architects, blame manufacturers for short-sightedly over-hyping their own products, but don’t blame the turbines. It would be a mistake if we were to dismiss the technology as a result. Small wind still has an important role to play, even if that role is more limited than many people hoped.

Read Full Post »

zcc III: onsite, offsite, and the role of private wires

Posted in biomass, chp, Code for Sustainable Homes, energy, engineering, private wire, renewable energy, SAP, sustainability, wind turbines, zero carbon, tagged on January 8, 2009| 2 Comments »

From the zero carbon consultation, you can see that CLG has accepted that we need to resolve the onsite / offsite question. They have also moved away from the requirement for private wire networks or “direct connections” between generators and homes since it caused all sorts of problems.

So positive moves from CLG, but there is still a huge amount of confusion over what onsite and offsite actually mean. This is a crucial issue since only onsite energy will count towards carbon compliance, while offsite energy is only likely to count as an allowable solution.

(more…)

Read Full Post »

zero carbon consultation II: summary

Posted in Code for Sustainable Homes, energy, engineering, private wire, renewable energy, SAP, stamp duty exemption, sustainability, zero carbon, tagged , on December 30, 2008| 3 Comments »

In case you don’t fancy wading through it, this is a brief summary of the zero carbon consultation doc. While nothing will be finalised until next summer (after they’ve ruminated over the responses), the document does give some insight into the way CLG is leaning on some issues.

At the core of the document is the government’s preferred framework for reaching zero carbon. In order of priority:

  1. A minimum standard of energy efficiency will be required.
  2. A minimum carbon reduction should be achieved through a combination of energy efficiency, onsite low and zero carbon (LZC) technologies, and directly connected heat. This is referred to as achieving carbon compliance.
  3. Any remaining emissions should be dealt with using allowable solutions, including offsite energy.

(more…)

Read Full Post »

DH standards and customer heat charter on the way

Posted in chp, engineering, london, tagged , , , on December 4, 2008| Leave a Comment »

Made it in the paper this week.

Casey Cole of low carbon consultant, Fontenergy, said the unregulated nature of heat has led to some “questionable practices” and needed outside regulation: “Both a technical standard for heat networks and a customer charter for heat are very welcome developments and we’ll be helping LEP with their work alongside the CHPA.

“While many buildings in London are now “district heat ready”, to date there’s been no common standard to ensure these schemes are actually able to connect to each other. In addition, rules for the provision of heat will give greater protection to customers and hopefully unify the many disparate methodologies in use at the moment.”

Read Full Post »

biomass blog

Posted in biofuel, biomass, chp, climate change, energy, engineering, renewable energy, sustainability, tagged , on October 15, 2008| Leave a Comment »

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!

Read Full Post »

payback periods – clients gone mad

Posted in climate change, energy, engineering, renewable energy, sustainability, tagged , on September 23, 2008| 1 Comment »

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.

Read Full Post »

Building Mag says biomass only efficient if used within 20 miles

Posted in agriculture, biofuel, biomass, climate change, energy, engineering, renewable energy, sustainability, tagged , , on August 21, 2008| 6 Comments »

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.

Read Full Post »

FEMA says: convert your car to wood gas

Posted in biomass, chp, climate change, energy, engineering, renewable energy, sustainability, tagged , , on August 5, 2008| 3 Comments »

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.

Read Full Post »

liquid biofuel CHP: officially renewable or not?

Posted in agriculture, biofuel, biomass, chp, climate change, Code for Sustainable Homes, DER Calculation, energy, engineering, london, renewable energy, SAP, stamp duty exemption, sustainability, tagged , , , , on July 25, 2008| Leave a Comment »

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.

Read Full Post »

UKGBC: Boom! Take that BRE!

Posted in Code for Sustainable Homes, energy, engineering, renewable energy, sustainability, tagged , , , on July 15, 2008| 2 Comments »

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?

Read Full Post »

« Newer Posts - Older Posts »

Design a site like this with WordPress.com
Get started