Burning ambition energises Shetland

It was a project that was born in the early 1990s when the Shetland Islands Council – which had for several years operated an incinerator that simply burned rubbish – was faced with new environmental regulations with which the existing plant couldn’t comply.

Eager to make investments that benefited the community, the Shetland Charitable Trust studied examples of successful waste to energy schemes elsewhere, particularly those in Denmark, and both the Council and Trust initiated the main elements of the project in 1997, with the first customer connected the following year.

The project was a pioneering one, now recognised by the Scottish government which has set a target of 2040 for all Scottish homes to have an Energy Performance Certificate of band C and to reduce residential heat demand by 15% and non-residential heat demand by 20%.

ISLAND IDEAL: SHEAP’s Energy Recovery Plant burns domestic, commercial and industrial waste to produce heat for approximately half of Lerwick’s homes and buildings.

In Shetland, the Council’s contribution involved building a new incinerator to heat large volumes of water and serve the needs of what was to become a district heating network, one that makes customer installation straightforward via a heat exchanger that enables heat to be transferred from the hot water main into a separate domestic pipework giving customers access to central heating, whenever they need it and an unlimited supply of hot water.

Crucially, the new Energy Recovery Plant (ERP), run by the local authority, overcame the environmental shortcomings of the old incinerator and enabled waste that couldn’t previously be recycled to be transformed into useful heat, generating 7MW of energy and burning some 23,000 tonnes of waste per year. 

The network consists of a Flow and Return main line with connection supply pipes to each individual customer for interface with their internal systems via an internally mounted heat exchanger which replaces conventional oil boilers, solid fuel fires and electric storage heaters.

Derek Leask, executive director at Shetland Heat Energy and Power Ltd (SHEAP) which is one of the largest and longest running heat operations in Scotland says that the organisation is committed to providing low carbon, waste-to-energy heat to Lerwick’s homes, hospitals, leisure centres, local government buildings, care homes and commercial entities and to help address fuel poverty and reduce carbon emissions.

“Twenty years ago there was a far-sighted multi-million pound investment when Shetland Islands Council decided to build an incinerator that was compliant with the latest emissions legislation and to use waste to provide energy for a district heating scheme.

“That entailed laying 30 km of pipeline in Lerwick to pump hot water to houses, hospitals schools, leisure centres and businesses which we are able to deliver at around a third of the price of electricity.”

That is an obvious benefit for many islanders, especially those living in social housing and facing the challenges of fuel poverty, the eradicating of which the Scottish government says is “crucial to achieving a fairer, socially just and sustainable Scotland”.

Leask adds: “If the waste that is being incinerated was simply going into landfill the significant amount of methane produced would be a bigger problem than the carbon dioxide as it’s around 20 times more potent than CO2. Our system prevents that methane going into the atmosphere so it’s having a positive effect.

“We were the first in Scotland to go down that road and recently the Scottish government is seeing the benefit of district heating networks as a weapon in the fight against climate change, one which will help to achieve its decarbonisation targets.”

PIONEERING: Derek Leask of Shetland Heat Energy and Power Ltd (SHEAP). 

He thinks that other regions in the UK might be surprised at the degree of innovation that has been put into practice in a relatively remote island community. In 2017 the new Anderson High School and its halls of residence began to take advantage of the system and before electricity companies began installing smart meters SHEAP had already introduced a radio system that could transmit its customers’ meter readings.

There are other beneficiaries of the ERP. Close neighbor Orkney does not have a similar incinerator. “Shetland Islands Council has an arrangement with Orkney that means we are able to take all their organic waste and use it for the district hearing scheme – which effectively allows us to provide an environmentally positive and affordable outcome for their waste management and is an additional benefit,” says Leask.

SHEAP is run as a commercial operation but any profits generated go to help Shetland Charitable Trust and its subsidiaries that focus on arts, heritage and recreation. 

SHEAP has some 1200 domestic and 200 non-domestic customers, which include hospitals, businesses and council buildings taking in around 6000 people. However, there are challenges that Leask would still like to resolve. “We have a waiting list of 300 people looking to connect individually to the system and while there are loan and grant schemes that allow domestic customers in Scotland to have new, more efficient, fossil fuel heating systems installed, that type of funding hasn’t been available for connecting to our system so far. This seems a bit of an anomaly with the government targets on climate change. 

“We’re currently in discussion about how that could be changed especially given the growing acceptance and acknowledgement that district heating networks represent a positive way to help in the decarbonisation of domestic and business heating and it would make sense for the public to have access to the same degree of funding to enable connection to our distribution network which has much less environmental impact” 

“We also believe that heating networks such as ours should be included on the renewable heat incentive scheme. This would increase its attraction to customers and allow for further expansion. We feel that waste-to-energy schemes are having at least the same positive environmental impact as many different types of renewable energy which are currently subsidised with RHI, and probably more so in some cases. 

With the ability to reach a large mass of customers, we can intervene in high carbon energy use much quicker than the development of some of the new alternative renewable projects.” 

SHEAP is not standing still either. Upcoming planned improvements to the Energy Recovery Plant will result in more energy being produced and the company is actively looking at technical solutions to allow this to be utilised. Plans are underway by the local housing association to build up to 300 residential units in Lerwick,  many of which will be for social housing. These are the customers SHEAP wants to reach and discussions are underway on how to extend the network to provide energy to this development. Other initiatives include a project to take waste heat from the Lerwick electrical power station. 

Leask concludes: “The world is basically in a climate emergency. We understand operations like district heating can go a long way to helping with the decarbonisation of Scotland’s energy provision. We’re keen to remain at the forefront of this and are continually looking at ways of expanding the Lerwick district heating scheme, making it more efficient and playing our role in reducing emissions from energy in Scotland.”