Motorway noise barriers as solar power generators

Abstract

During 2001 the Highways Agency (HA) commissioned TRL Limited to undertake a study to assess the feasibility of generating renewable energy on motorways and trunk roads. This study recommended that the HA undertake a full-scale trial of noise barriers incorporating solar panels. In 2004, two rows of solar barriers were installed in a cutting to the east of junction 9 of the M27. The trial was carefully monitored and showed that south-facing land alongside highways can successfully be used for solar barriers. In terms of maintenance, rainfall was effective in washing the panels; however, vegetation needs to be cut back at least annually unless the barrier is installed in a paved area. There was no evidence that drivers were distracted by the presence of the barriers or that noise reflected from the barriers would create any significant disturbance opposite the site. Although solar barriers are a feasible means of generating renewable energy on the highway estate, a whole-life cost analysis showed that the electricity generated over 30 years would not pay for the cost of installing the barriers unless the price of electricity was many times its current value.