Alternative energy may be an easy way to describe the many ways, other than fossil fuels,to heat,light and power public sector buildings.The snag with the phrase is that it puts alternatives in a box labelled ‘special projects’,nothing to do with everyday energy decisions.
This approach has two dangers.It ignores the fact that well within the lifetime of today’s building projects gas and oil will become non-alternatives as their costs and availability turn all the present energy equations on their head.Treating alternative energy as special also means that projects tend to be put forward without looking at the economic case or the design,installation and long term support the building might then need.
Pick the low hanging fruit
Alternative systems should then be judged on their merits to reduce greenhouse gases by replacing fossil fuels,using the acid test of ‘bang for your buck’or more prosaically,tonnes of CO2 for your £. Based on the many building and alternative systems Viessmann has been involved with - from solar heating to PV - a practical pecking order has evolved.As you can see from the table this puts solar heating and ground source heat pumps top of the order in terms of environmental effectiveness v. capital cost.
Of course this is highly simplified but what it does is to point to the first and obvious choices of the easiest savings,on the assumption that capital cost is a factor.It also highlights that in most buildings,80% of the energy use flows through the boiler,so the heating and hot water loads offer the obvious first target.
What about the practical points of design,installation and service life of equipment?There have been many examples of buildings where an interesting set of alternative energy systems have been pushed in,only for them to be quietly taken out and replaced in a year or two.While this might be part of a learning curve it is an expensive teaching method.What it should be teaching us is to concentrate on systems where expertise in product manufacture,system design, installation and service is being widely developed in the UK H&V industry.
Putting alternative energy in a box
This learning curve approach has also meant that each individual system,be it solar water heating or heat pumps or whatever,is treated individually rather than seeing them as ‘ Lego’;selecting the energy options in combination that will best suit the building. Even combining alternative systems with conventional where it makes economic sense.This disparate approach is driven by the fact that the technology is at an early stage and few examples exist where all or most of the equipment can easily be combined,installed and controlled.
In solar heating and ground source heat pumps this ‘Lego’combination of equipment,backed by skills and service is moving rapidly into place.In the case of Viessmann we have drawn on decades of experience in Europe where alternative energy use is well ahead of the UK.The result of this experience is to put alternative energy systems in a box which incorporates the key elements of the system, controls,storage vessels and pumps so that the installer bolts on the solar or heat pump connections without each time having to invent the entire system.
European experience has also pointed firmly to ensuring that everyone in the decision, from the manufacturer through to the client, and his energy management team, are involved.For our part we have been holding briefing sessions on alternative energy systems for public sector professional staff as well as working with H&V designers and installers to bring them the different skills needed with alternative energy.
This has meant that this year we shall be seeing over 200 ground source heat pumps installed in a wide variety of buildings,from homes through offices to park and ride terminals.Installations of solar heating in the public sector are even more widespread from large scale sheltered housing to offices and leisure centres.
In the majority of these projects the requirement has been for systems that are a practical, straightforward alternative or addition to the fossil fuelled heating and water heating system and one that the building users and their staff can manage simply.
We have no alternative but to make alternative energy part of the mainstream,not at any cost,but as a technology that can be in everyday use in many of our buildings, delivering real energy savings and making their contribution to a greener world.
Case Study
Southport’s new Eco visitor centre has two roles.It is the terminus for the town’s park and ride service and also a showcase and teaching centre explaining sustainable construction and renewable energy.Over 500,000 visitors are expected each year.
Heating for the teaching areas, staff rest rooms, facilities and offices comes from an underfloor system powered by a 6kW Viessmann Vitocal heat pump.Other sustainable features of the building include six square metres of Viessmann Vitosol panels providing DHW. Rainwater harvesting is used for the WC’s and a wind turbine will contribute to the building’s electrical power.
The heat pump system was fitted by local installer Multiserv and the ground boring work was carried out by Geoscience.Multiserv chose a Vitocal heat pump of 10kW which was supplemented with a 6kW electrical flow heater.Dave Halton of Multiserv explains: “The pump was sized on the basis that with a Vitocell 600 litre buffer tank the heat pump will meet design loads on all but a few days per year so that from a capital cost point of view the dual approach made sense.” Eight 28 metre deep bore holes were used for the heat extraction.
The Eco centre was funded by Sefton Council with National Lottery and Clear Skies grants.The main contractor was Keir North West and the M&E contractor was Hills Electrical & Mechanical.
