Frequently asked questions

Gren is a green energy company. We develop and deliver energy solutions, ranging from sustainable district heating to renewable and industrial energy, to meet the daily needs of our customers and communities. Gren is already an established energy supplier in Northern Europe, where we run approximately 630 kilometres of pipelines under cities in Estonia, Finland, Latvia & Lithuania, warming nearly 180,000 homes and 600 commercial premises. Our managed networks, replacing individual boilers in homes and premises, are a mainstay of heat consumption in Scandinavia and northern Europe.

Gren entered the UK market in May 2023 when it acquired 11 energy assets from investment managers & developers Equitix, These assets consist of an energy from waste plant, three Combined Heat and Power (CHP) plants, and seven biomass boiler plants, and offer heat to heat networks, industrial, public, and commercial counterparties, as well as baseload electricity to the local grid. All assets use locally sourced fuels. You can read more about our UK portfolio here.

Mike Reynolds was appointed CEO of Gren Energy Ltd in June 2023. Mike and his team will oversee the growth of the initial portfolio and leverage Gren’s expertise as a market leader in district energy to partner on new projects and make targeted acquisitions.

Gren’s decision to enter the UK market is underpinned by the country’s ambitions to reach net zero emissions by 2050. The UK is expected to transform how it generates and transports energy, and Gren sees the UK as an exciting opportunity. We are accelerating our presence in the UK to ensure Gren plays a key role in providing local, affordable green energy for all.

Our vision is to acquire, scale and develop low carbon infrastructure which generates, distributes, and connects homes and businesses to secure, local energy sources. Our approach will create jobs, and boost investment and local economies while lowering energy bills, increasing efficiency and driving carbon from our energy supply.

Our proposition is simple: An offer which future proofs our customers’ energy needs, provides great customer service, and leads the way on how to run and decarbonise assets while creating value.

Gren Energy Ltd is looking at a wide range of opportunities in the district heating market and in the supporting infrastructure, such as power generation and storage and private electrical networks. We are open to considering projects of various sizes.

Gren is owned by Partners Group, a global private equity firm. Gren was formerly known as Fortum’s Heating & Cooling Business in the Baltic countries, where it has a track record of pioneering energy systems and excellence in delivery spanning decades. It rebranded as Gren in 2021 when it was acquired by Partners Group, acting on behalf of its clients.   

Decentralised energy is energy based at or near the energy user and has an integral role to play in the delivery of a flexible, smart energy future. Decentralised energy solutions are low carbon and efficient, offer users more choice in how they meet their energy needs and control over their energy costs and reduce network investment costs as long-term demand decreases and/or users offer demand flexibility.

Decentralised energy is also known as distributed energy. Distributed Energy Resources (DERs) are small-scale energy resources usually situated near sites of electricity use, such as rooftop solar panels and battery storage. Their rapid expansion is transforming not only the way electricity is generated, but also how it is traded, delivered and consumed.

District heating, also known as a heat network, is a system that uses a singular central heat source to distribute hot water through a network of insulated pipes to multiple individual dwellings.

The structure is usually used to fulfil heating and hot water requirements in apartment complexes. However, as the UK market develops, district heating is also being adopted in large-scale buildings associated with educational and commercial operations. Because district heating efficiently delivers low-carbon, cost-effective heat, the UK government has been quick to acknowledge it as a vital solution in an accelerated move towards low-carbon energy systems.

District heating schemes currently supply around 2% of the UK’s heat (around 200,000 homes). But with an estimated 50% of buildings in the UK located in areas of suitable density for heat networks, the system has the potential to have a far greater impact. Driving forward low-carbon energy solutions such as district heating makes achieving net zero considerably more achievable, as we drastically reduce the use of fossil fuels by opting to deliver heat from communal heat sources.

Heat networks will deliver a huge part of the work needed to deliver net zero, accelerating the low carbon transition and lowering energy bills thanks to their unique ability to integrate renewable energy sources and utilise waste heat. Ultimately, heat networks are the only internationally proven route for decarbonising heat at scale – but this hasn’t always been recognised by the right decision-makers.

Critical heat network infrastructure, heat networks and the value they offer will be a huge part of the conversation on how the UK will achieve its New Zero targets.

District Energy is a term which may refer to thermal energy (such as district heating and district cooling) or electricity (such as distributed generation – the means of producing electric energy and/or storage and distribution in a distributed manner. Distributed Energy Resources (DERs) are small-scale energy resources usually situated near sites of electricity use, such as rooftop solar panels and battery storage. Their rapid expansion is transforming not only the way electricity is generated, but also how it is traded, delivered and consumed.

District heating is a kind of thermal district energy. District energy is a wider term which also includes cooling and distributed generation.

Heat networks are not a new technology: They are an established and well-proven form of infrastructure that are now entering a new era. The UK’s first district heating scheme was built in Pimlico in London in the 1950s to funnel waste heat from Battersea Power Station to thousands of homes and businesses. Heat networks grew in popularity and some councils bought into them enthusiastically, particularly for social housing.

However, district heating is now more commonly found in parts of Europe, particularly the Baltic and Nordic countries, Germany and the Netherlands. Building at scale is the next step for heat networks. Gren has more than 20 years of experience in serving customers and partnering with towns and cities in the Baltic region by developing sustainable generation assets and efficient and reliable district heating networks. Gren sees a great opportunity in the UK as one of the fastest growing district heating markets in Europe.

Gren uses proven technology to deliver clean and secure heat and power, building resilience to climate change and future-proofing our homes, industries and public services.

While heat networks only supply 2% of the UK’s heating demand today, they are an internationally proven route for decarbonising heat at scale and will need to see significant growth if we are to successfully decarbonise our towns and cities.

With an estimated 50% of buildings in the UK located in areas of suitable density for heat networks, the system has the potential to have a far greater impact. Driving forward low-carbon energy solutions such as district heating makes achieving net zero considerably more achievable, as we drastically reduce the use of fossil fuels by opting to deliver heat from communal heat sources.

Deep geothermal, which can be fed into heat networks, has its greatest potential in meeting this heating challenge. It will also help reduce demand on the grid created by transitioning all the UK’s heating to electricity.

As part of the UK’s trajectory to decarbonise buildings and reach Net Zero carbon emissions by 2050, as well as the recently announced target to reduce energy consumption from buildings and industry by 15% by 2030, heat networks are set to play a growing role in the supply of low-carbon heat to homes, non-domestic buildings and the public sector.

Against the backdrop of the gas price crisis, low-carbon heat networks also represent a means of addressing affordability issues by supplying energy cost-effectively, and at fair prices, to consumers.

Heat networks can also support system flexibility where they have centralised thermal storage attached or use multiple heat sources, allowing them to shift demand. Together with opportunities to utilise waste heat, this can help achieve efficiencies across the power system and reduce emissions.

It is estimated that 19% of the UK’s greenhouse gas emissions come from warming up the places we live and work, with more than three-quarters of this coming from domestic buildings. Most houses in the UK rely on gas boilers, but the British Government has moved to phase these out in the next five years.

District heating currently only serves 2% of UK buildings and forecasts from the Department for Energy Security and Net Zero (DESNZ) show that over 18% of UK heat demand could be met by switching buildings from running on individual gas boilers to centralised district heating networks

Heat networks are an internationally proven route for decarbonising heat at scale.

There are many different technologies that can provide the input to a heat network, including power stations, Energy from Waste (EfW) facilities, industrial processes, biomass and biogas fuelled boilers, and Combined Heat and Power (CHP) plants – which can include gas-fired units, fuel cells, heat pumps, geothermal sources, electric boilers and solar thermal arrays. All Gren’s assets in the UK use locally sourced fuels.

District heating has many advantages over traditional heating systems, including increased efficiency and sustainability.

Combined heat and power (CHP) is a highly efficient process that captures and utilises the heat that is a by-product of the electricity generation process. By generating heat and power simultaneously, CHP can reduce carbon emissions by up to 30% compared to the separate means of conventional generation via a boiler and power station.

The heat generated during this process is supplied to an appropriately matched heat demand that would otherwise be met by a conventional boiler. CHP systems are highly efficient, making use of the heat which would otherwise be wasted when generating electrical or mechanical power. This allows heat requirements to be met that would otherwise require additional fuel to be burnt.

For many organisations, CHP is the measure that offers the most significant single opportunity to reduce energy costs and to improve environmental performance, with existing users of CHP typically saving around 20% of their energy costs. Other advantages include reduced transmission and distribution losses and increased fuel supply security. CHP typically has an efficiency of over 80%, and operators can save up to 30% on carbon emission.

A Combined Heat and Power (CHP) plant consists of an electrical generator, combined with equipment for recovering and using the heat produced by that generator.

Biomass, meaning organic material from living things, can be used for low-carbon energy generation. It is projected to play an important role in meeting UK net zero targets, requiring a substantial expansion in domestic production.

Bioenergy is currently the second largest source of renewable energy in the UK, generating 12.9% of the total UK electricity supply in 2021. When combined with carbon capture and storage (BECCS), bioenergy may deliver negative emissions (PN 618), which could contribute towards the UK’s legal commitment to reach net zero carbon emissions by 2050. Demand for biomass is expected to rise in the UK and globally to supply BECCS, transport fuels, and other materials and chemicals. The Climate Change Committee (CCC) recommends prioritising the most effective biomass end-uses for carbon sequestration. The UK Government is developing a ‘priority use framework’ that follows this principle and aims to ensure that biomass is targeted towards use in sectors where options for decarbonisation are limited. This framework will be explored further in the UK Government’s upcoming Biomass Strategy.

Alongside the use of forest residues, perennial energy crops have been identified as a future source of domestic biomass as they are fast-growing and energy dense. When planted in the right context, perennial energy crops may also provide positive environmental impacts alongside social and economic co-benefits. The expansion of domestic biomass production faces social, economic and technical challenges. Robust and transparent sustainability and land-use policy frameworks will be required in addition to targeted support schemes across multiple sectors to address these.

Heat networks are not a new technology: the Romans used a system of underground tunnels to distribute heat from large furnaces to public buildings and homes. However, the first generation of modern district heating systems emerged in the late 19th and early 20th centuries.

The first modern district heating system in the world was installed in Lockport, New York in 1877. It was designed by Birdsill Holly, a local inventor, and used steam from a central coal-fired boiler to heat several buildings, including a church, a school, and a hospital. The system was successful and was expanded over time to include more buildings in the area. Holly’s design was also adopted in other cities in the United States, such as Boston and Philadelphia, and helped pave the way for the development of modern district heating systems around the world.

However, it was not until the 1920s that district heating systems began to be widely adopted in Europe. In 1923, the first modern district heating system in Europe was built in Frankfurt, Germany. Other European cities soon followed suit, with district heating systems being built in Copenhagen, Denmark in 1925, and Stockholm, Sweden in 1929.

During World War II, district heating systems were used extensively in Europe to provide heating to buildings that had been damaged by bombing. After the war, district heating continued to grow in popularity, particularly in communist countries like the Soviet Union, where it was seen as a way to centralise energy production and distribution.

Today, first generation district heating systems are still in use in many parts of the world. They typically use a central heating plant to generate heat, which is then distributed to buildings through a network of pipes.

The UK’s first district heating scheme was built in Pimlico in the 1950s to funnel waste heat from Battersea Power Station to thousands of homes and businesses. In the 1960s and 1970s, shared heating networks stared being used in other urban areas, predominantly in blocks of flats. Many of these schemes are still in operation today. However, district heating still only makes up around 2% of the UK energy market – although that still equates to 200,000 properties.

District heating was first used on a widescale in Denmark. During the 1973 oil crisis, the price of a barrel of oil quadrupled, leaving Denmark in a very difficult situation because, at the time over 90% of its energy came from imported oil. In the aftermath of this crisis, Denmark changed energy policy and started investigating heavily in renewables and district heating. Forty years later, 63% of its citizens are supplied by district heating networks and Denmark is a net exporter of oil.

Heat networks are also now common in Scandinavia, Eastern Europe, Germany, South Korea and major cities in the USA and Canada. There are also increasing in the growth regions of China.

Since 2000, as energy prices have risen and the UK government has looked for ways to cut carbon emissions, district heating has been increasingly recognised as an important part of the UK’s energy future.