On Farm Renewable Energy

What is renewable energy?

Renewable energy is energy produced from a natural and renewable source that is constantly replenished, such as sunlight or wind. Also referred to as ‘alternative’ or ‘clean’ energy, it refers to sources of energy offering an alternative to the historically used non-sustainable sources, such as coal, or oil. This type of energy is an essential element of the country’s drive to achieve Net Zero emissions by 2050 and ultimately mitigate the effects of climate change.

Renewable energy generation and the adoption of low-carbon solutions offers agricultural and rural business owners the opportunity to diversify their income, minimise energy costs, reduce harmful greenhouse gas (GHG) emissions and in this way their impact on the environment.

There are 9 key types of renewable energy / clean energy solutions being utilised on farms and estates in the UK.

  1. Anaerobic Digestion & Biogas
  2. Biomass
  3. Energy efficiency / management systems
  4. Energy storage systems
  5. Heat Pumps
  6. Hydropower
  7. Low-emission vehicles and machinery
  8. Solar Power
  9. Wind Power

Renewable Energy Icon Anaerobic Digestion & Biogas

AD and Biogas

Anaerobic digestion, often referred to as simply ‘AD’, is the natural breakdown of organic matter by micro-organisms in the absence of air.

The organic matter, known in this case as ‘feedstock’, comes from a variety of sources including crops, food waste, slurry and manure. The feedstock is put into a sealed tank or digester, to be digested by the micro-organisms, which releases a methane-rich gas (aka biogas), CO2 and a valuable biofertiliser known as digestate.

The biogas can be used to generate heat and electricity via a combined heat and power (chp) engine or cleaned and upgraded to biomethane to be injected into the gas grid or used as a transport fuel.

The digestate produced can be used on farms as a nutrient-rich fertiliser.

In addition to generating renewable energy and producing digestate, Anaerobic Digestion (AD) plants also have a pivotal role to play in the reduction of global methane emissions – recycling waste and reducing the associated emissions. The CO2 produced can also be captured and taken to market.


Renewable Energy Icon Biomass

Biomass

Reducing and/or effectively managing the amount of energy used on a farm should be part of any plan to make the business more sustainable and reduces its impact on the environment. An energy audit, identifying where and how energy is being used, is also an important first step when considering the size of renewable energy system required.

There are many ways to save energy on a farm or estate including insulation on buildings, improving ventilation, swopping light bulbs for LED equivalents, maintaining equipment, improving irrigation, utilising heat exchangers to capture ‘waste’ heat and investing in renewables or low-carbon energy solutions.

Many energy companies offer a ‘green’ supply contract, so energy coming from a renewable source, providing economic and environmental benefits.


Renewable Energy Icon Energy efficiency / management systems

Energy efficiency min

Reducing and/or effectively managing the amount of energy used on a farm should be part of any plan to make the business more sustainable and reduces its impact on the environment. An energy audit, identifying where and how energy is being used, is also an important first step when considering the size of renewable energy system required.

There are many ways to save energy on a farm or estate including insulation on buildings, improving ventilation, swopping light bulbs for LED equivalents, maintaining equipment, improving irrigation, utilising heat exchangers to capture ‘waste’ heat and investing in renewables or low-carbon energy solutions.

Many energy companies offer a ‘green’ supply contract, so energy coming from a renewable source, providing economic and environmental benefits.


Renewable Energy Icon Energy storage systems

energy storage

Energy storage systems enable energy from renewables to be stored, released, and used at the times required. They have a key role to play in the decarbonisation of energy systems and the achievement of Net Zero targets.

Renewable energy systems such as solar panels or wind turbines will generate an abundant amount of energy while the sun is shining or the wind blowing – adding a storage system to your site will allow this energy to be used at the time(s) it is needed and during periods of less generation (eg at night), reduce any electricity being used from the grid and reduce bills further. These systems also provide a means to maximise the value of the energy being generated, by storing and selling it when power prices are at their highest.

They are central to the growth of the electric vehicle (EV) market, plus seen as an essential addition to energy networks, constantly striving to match energy supply with demand. The UK government estimated that energy storage systems could save the energy system up to £40 billion by 2050, by supporting the deployment of more low-carbon energy and transport technologies.

There are many types of storage solutions, with the technology being developed all the time, including batteries (lithium, flow or lead-acid), thermal storage systems, pumped hydro storage (see hydropower entry) and hydrogen solutions.


Renewable Energy Icon Heat Pumps

Heat pumps image

Heat pumps absorb energy from one source, transforming it to useful heat, working in a very similar way to a fridge. Where heat is transferred out of a fridge, a heat pump absorbs heat into a refrigerant in an evaporator, which changes from liquid to gas in the process. This gas is compressed, increasing its temperature further. This heat is transferred to a building’s heating system via a heat exchanger. Once the refrigerant has cooled and returns to a liquid state in a second heat exchanger, it passes through an expansion valve to decrease the pressure, returned to the evaporator and the cycle starts again.

Heat pumps produce renewable energy and do not generate any CO2. They do use electricity to run, so to be completely renewable the power required should come from a renewable power source, such as solar panels or wind turbines. As they transfer heat rather than generating it, heat pumps are a very efficient heating option, however their level of efficiency does depend on how hard they must work to heat a room/building, so a well-insulated building is recommended. 

There are three main types of heat pump:

  • Air Source – a fan helps to absorb air from outside
  • Water source – pipes absorb energy from an external water source, i.e. a lake or pond
  • Ground source – pipes absorb energy from the ground

Heat pumps can also be used for cooling where necessary and as a result have many applications in agricultural and rural communities, including grain drying, underfloor heating, cold stores, greenhouses and pre-heating water for a dairy.


Renewable Energy Icon Hydropower

Hydropower

Hydroelectric power is generated by using flowing water to turn a turbine which is connected to an electric generator. The amount of power a site can generate depends on the level of height difference, known as head, between the top of the intake and turbine, and the flow rate – the volume of water flowing across the turbine.

The main types of onshore hydropower systems are:

  • Run of river – Water is diverted into a channel to spin the turbine to generate a continuous supply of electricity – the base load. It is a system whereby little, or no water is stored and as such subject to seasonal river flows.
  • Storage hydropower – A large system, using a dam to store water in a reservoir, with electricity produced by releasing said water through a turbine.
  • Pumped storage hydropower – Two reservoirs at different altitudes are required. Energy is created by the top reservoir releasing water to the lower reservoir via a turbine.

Renewable Energy Icon Low-emission vehicles and machinery

Low emission vehicles

As part of the global push to decarbonise the transport system, there are now a vast array of hybrid and/or fully electric vehicles (EVs) to choose from, allowing owners to reduce their environmental impact and their fuel bills. Tax benefits are also available.

Agricultural machinery is also being decarbonised, with efforts being made by manufacturers to produce machines utilising fuel sources such as biomethane (see biogas section) and hydrogen.

Renewable energy generators are able to maximise the benefits of these type of vehicles, by using the energy generated on site to charge or refuel the vehicle/machine in question.

Farmers and landowners can also take advantage of the associated opportunities such as becoming part of the EV charging network or by supply biomethane to be used as a transport fuel.


Renewable Energy Icon Solar Energy

Solar

There are two types of solar panel – solar photovoltaic (PV) and solar thermal. While both absorb energy from the sun to create usable energy, PV systems create electricity, while thermal systems are used for heating. They can be installed on roofs or the ground – the larger ground mounted arrays normally being referred to as solar farms, which are developed on land typically leased from its’ owner.

The energy generated by solar technologies can be used on site, with the excess sold to the grid. Many solar systems are accompanied by a storage system, enabling the energy to be used at the necessary time.

Applications of solar energy on a farm or estate include lighting, heating of water, security such as electric fences or gates, drying crops, power for diversification enterprises and/or the everyday energy requirements of homes and businesses.


Renewable Energy Icon Wind Power

wind power

Using wind to turn turbines and produce electricity, these systems are located both on and offshore and generated over 75GWh of electricity from both sources in 2020. Enough to power 8.4 trillion LED light bulbs. Given our agricultural/rural focus, Energy Now covers the onshore sector.

Renewable energy generated by onshore wind offers the most cost-effective choice for new electricity in the UK, being cheaper than gas, nuclear, coal and other renewables.

The agricultural sector has been instrumental in the development of the onshore wind sector, with many farms hosting at least 1 turbine and others entering long-term leasing arrangements, to enable many wind turbines (a wind farm) to be developed on their land. As with the other technologies, the power generated can be used on site, with the excess sold back to the grid, thus enabling the farmer or landowner to decrease their bills and environmental impact, while increasing their income.