Clarity on Performance

Following the piece I did for BBC Country File on Feed in Tariffs, I found myself in an interesting debate in the letters section of New Civil Engineer. As usual, this started me thinking, this time about communicating sustainability to the public.

The standing of climate science is currently pretty low as it has become apparent that scientists overstated some of the issues. The same happens when Government makes overblown statements about the effectiveness of renewable energy in desperate attempts to meet its own policy targets.

The announcement launching Feed in Tariffs suggested that householders could earn £900 per year from installing PV. They failed to mention that this was only true for the South East of England, on a perfectly pitched roof, facing due South; hardly representative of the average. Further, such an array would be a little too large to fit on the roof of an average 3 bed terraced house and would cost £13,000-£15,000.

I believe that there must be much more clarity on the actual performance of real systems. We have already seen the market for DIY wind turbines killed off by public reaction to the overstatement of returns by manufacturers. This has reduced the choices for homeowners, even where these could have been installed in worthwhile locations. For engineers and Government to similarly hype up the potential returns from renewable energy does not do the industry any favours.

We need to build public trust and support for renewable energy by making realistic assessments of the returns they can expect from real installations, not theoretical ones.

Ignorance Isn’t Bliss

A design review this afternoon brought home just how critical the low carbon knowledge gap really is. Two architects presented schemes for projects with high sustainability ambitions. Both were labouring under misapprehensions about daylight and natural ventilation because both had been advised by their engineers that everything would be fine. Unfortunately neither architect had sufficient knowledge to challenge their engineers’ assertions.

It transpired that the ventilation would be fine because the engineers, in both cases, were planning to add fans, so the systems would work when natural ventilation failed. A quick examination of the buildings in question revealed these fans would have to be relied on for ventilation about 95% of the time – hardly natural ventilation.

The daylight issues were also similar; deep plan buildings with fully glazed facades in compensation to let enough light in! Once again, an engineer had calculated the average daylight factor and assured the architect that everything would be OK. I estimated that the light would vary by about 60:1. With such high contrast the interiors will appear deeply gloomy against the over-lit perimeters and result in excessive use of electric light.

Neither building was engineered to achieve the architectural ambition. Both displayed classic mistakes which we teach architectural students to avoid. However, a practicing architect has to deal with many conflicting issues and must be able to rely on their engineer. Yet, engineers are taught to design with fans and electric lights, not to manipulate the building form to promote natural airflow and light.

How many buildings fail by falling between architects and engineers who lack a common language? We must not only join up architectural and engineering education, but we must do it urgently.

Strata Tower


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The Strata Tower at Elephant & Castle featured heavily in the news last week. The developers are clearly very proud of their clever solution to addressing the London Plan’s requirement that 10% of a building’s energy be generated from on-site renewables. The building is to feature 3 turbines of 9m diameter for the princely cost of £1,300,000. However due to the small size and fixed direction these turbines are only expected to generate some 50MWh per year or just 8% of the building’s demand.

Let’s look at the alternatives:

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The well established Proven 15kW turbine has a rotor diameter of 9m and a single one of these costs about £50,000 to erect in a field. If sited in a suitably windy field you can expect to generate around 30MWh per year, but installations have been recorded that generate in excess of 50MWh. The same generation capacity as Strata for 4% of the cost!

On the other hand let’s consider Ecotricity’s turbine at the Ecotech centre in Norfolk.

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The first MW+ rated turbine in the UK this one weighs in at 1.5MW, and would cost about the same to install in today’s money as the Strata turbines. According to Ecotricity’s website this machine is generating 3,500MWh per year, 70 times as much as Strata is predicted to do!

This fad amongst local government to demand on-site renewable energy must stop; it’s eco-correctness gone mad! Rules like this force developers to waste money on eco-bling rather than investing in basic energy conservation and large scale renewables which can make a real difference.

 

 

Speed Kills

A roadside information sign exhorting me to slow down because ‘Speed Kills’ made me think today about how we communicate issues that perhaps people don’t want to confront, such as climate change and peak oil. We see exhortations such as this all the time, yet they don’t seem to be affecting people’s behaviour. Maybe this is because the message isn’t just wrong, it is patently so: speed evidently does not kill. There have been no recorded cases of motorists suddenly expiring as they pass the speed limit. No, it is suddenly stopping that kills most motorists.

I think it is the same with peak oil. It’s no use telling people to reduce their energy consumption, which they’re quite comfortable with, because of a possible future problem. It isn’t the present condition, but the change, that’s going to knobble us. The issue is that it will be so much worse if we don’t start preparing for the inevitable now. Like speeding in a car, it’s not the present rate of economic progress that is the problem, but what will happen when that progress is suddenly halted and we hadn’t prepared for it by slowing down.

When we are communicating messages about future risks we must avoid over-simplification and blatant fallacies or we will just be totally ignored.

I’m going to think about this and write more when I have made some connections.

Eco-Bling Rules

I should just briefly explain the name of this blog.

I started using the term eco-bling back in 2002 to describe the antithesis of my approach to low energy building design. Eco-bling is small scale renewable energy visibly attached to poorly designed, energy hungry, commercial buildings. It’s a zero sum approach as the benefit of the renewable generation is swamped by the energy demands of conventional building design. I advocate designing buildings that can achieve 50-80% carbon reductions through passive design and investing in de-carbonising the electricity supply at a national scale.

Well, over the last 5 years or so we have seen the proliferation of eco-bling rather than any real effort to improve our built environment. In my opinion this has largely been driven by eco-correctness amongst local politicians setting planning rules for totally in-appropriate on-site renewable generation at the expense of energy conservative design and large scale off-site renewables, which could actually make a real difference.

In a moment of frustration I voiced these opinions. I just happened to be in a press conference at the time and the rest as they say is history…

http://www.timesonline.co.uk/tol/news/environment/article6994439.ece

http://www.guardian.co.uk/environment/2010/jan/20/eco-bling-retrofitting-carbon-emissions