Goblin Combe Redevelopment: options for renewables
Investigating renewable energy options for a North Somerset environment centre
Project duration: January 2003 to July 2004
This project investigated different renewable energy options for a North Somerset environment centre - Goblin Combe Environment Centre, Cleeve, North Somerset.
The overall aim of the study was to investigate a range of renewable energy options for the site, produce a set of recommendations to be considered within the phased architectural development of the camp site as a whole and to explore the opportunities for community involvement and renewable energy awareness-raising and education among the site’s users. Specifically, the aims were:
- to undertake a technical options appraisal for renewable energy use at the site. This included solar, biomass, wind and heat pump technologies
- to produce best-estimate costings and payback periods for the range of technical options, incorporating options for any revenue streams from electricity generation
- to identify sources of finance for the implementation of systems
- to evaluate the environmental benefits, legal considerations and planning consent issues relevant to the proposed renewable energy installations
- to examine the potential for education and awareness-raising of the renewable energy aspects of the site among its visitors
An initial site survey identified the following as having potential for further consideration as part of a feasibility study:
- biomass heating
- solar water heating
- ground source heat pump
- wind power
The potential for providing space and/or hot water heating from a biomass boiler was examined. Goblin Combe Environment Centre owns 55 hectares of woodland around the camp site (see photo), two-thirds of which is plantation woodland, 80% of which is broadleaf. Under the terms of purchase, the Centre is obliged to continue to actively manage the woodland. This creates the potential for local woodland thinnings to be used as fuel for the boiler.
The options for incorporating a photovoltaic array were considered in order to meet all or part of the site’s electrical demand. Innovative roof-integrated systems (e.g. PV roof tiles) were considered, along with monitoring and display packages for educational use. Similarly, options for a solar water heating system to supplement the site’s hot water demand were examined and consideration was given to how it may be integrated with water heating capacity from other sources, e.g. a biomass boiler. A software design package was used to estimate energy production for options considered.
A ground source heat pump was also considered as an alternative option for provision of space heating within the building. The plans for the new-build dormitory block (now built, see photo) involve high levels of insulation and excellent all-round energy efficiency. These qualities complement the use of heat pumps in that they lower heat demand, reducing the installed capacity required and hence lower costs. Finally, options for small-scale wind power were considered. Costs, energy yields and planning issues were assessed for a range of stand-alone and roof-mounted devices. Issues regarding grid connection and electricity export were also explored.
The study concluded that biomass heating using a woodchip boiler could be a pragmatic, economically-viable option for space and water heating. Although not strictly considered economically viable, a PV installation is also suggested as part of a translucent glass canopy. This would fit well aesthetically and be a prominent example of renewable energy in action.
The report also recommends that demonstration-scale systems for solar water heating and possibly roof-mounted wind power be considered for awareness-raising opportunities. Ground source heat pumps, stand-alone wind and larger solar water heating systems were not recommended for reasons of economics, relative environmental benefits or planning issues.