Environmental Benefits

The main feature of Havannah Quay is how the energy to heat, cool and power it is going to be generated. Readers will know that there is some confusion over defining “green” developments, ranging from “carbon neutral” to “carbon zero”. For us it’s very simple. We are going to attempt by the end of the development programme to generate no carbon from the energy consumed on the site at all. So we have decided to call Havannah Quay “carbon free”. Here is how we propose to do that.
The overall size of the site currently stands at 33 acres. If all of the buildings constructed were powered from mains electricity, our engineers have estimated that it would consume in excess of 27 megawatt hours (Mw/h) of electricity at peak times. The first thing we are going to do is use ground source heat pumps (GSHPs) to provide heating. This involves pumping water down a number of boreholes; the heat from the earth is transferred to the water; when it returns to the surface, it is extracted and used to heat the buildings, just as with a central heating system powered by gas or oil. Installing GSHPs will dramatically reduce the electricity requirement on the site from 27 Mw/h peak to less than 10 Mw/h peak.

By using the latest and most efficient insulation in the construction process, we expect to make further energy savings. And all of the street lighting, car park lighting and building lighting will be by way of LEDs. LEDs use less than a quarter of the energy of the old lightbulb. Adding these energy savings together will reduce the 10 Mw/h peak to less than 6 Mw/h peak.

On-site production of electricity

Did you know that to power a 60 watt lightbulb in your home or office requires the electricity company to generate approximately 120 watts at the power station? This is because in the region of half the electricity is lost in the power cables. This means that the 27 Mw/h peak power required if the site was 100% powered by electricity would actually necessitate in excess of 50 Mw/h of electricity to be produced at the power station.

Of course, we are going to need some electricity on the site and to avoid the wasted energy referred to in the previous paragraph, we are going to generate this electricity on site using quiet highly reliable generators. Instead of using petroleum products as fuel, they will initially be powered by bio-fuel and later by hydrogen.

Conclusion

If we can achieve our ambitious energy goals and make the Havannah Quay development carbon free, it will be the first development of its size anywhere in the world that achieves this. Everybody talks about ‘green’ buildings but no one has actually done it. Imagine coming home from work and switching on the light or cooking something with the knowledge that you are not causing any carbon to go into the atmosphere or if you were at work in one of the new Havannah Quay offices and using your computer or making a cup of coffee all of the energy you used was being replenished without polluting our fragile Earth?