As record renewable energy production progresses rapidly in the UK, a sustainable green future looks closer than it ever has done.
Renewable energy in UK has provided more electricity to homes and business than fossil fuels during the third quarter of 2019.
Energy figures released by the Department for Business, Energy and Industrial Strategy (BEIS) produced earlier on this year showed that the UK’s production of electricity in 2018 was up 2.9% on 2017, driven by growth in oil, wind, solar, bioenergy, and waste.
Despite coal reaching a record low and declining by 25% and natural gas falling by 3.8% overall fossil fuel production increased. 2018 saw coal being responsible for just 1% of the UK’s total energy generation resulting in the county’s coal-fired power stations being completely unused for 12 days which was a record.
The Centre for Alternative Technology (CAT) has claimed that the UK has the ability to generate 100% of it’s energy supply from clean sources or carbon-neutral back-ups.
As the UK becomes increasingly more reliant on renewables it has become important for energy managers to look at how they can take on new technologies to better manage and monitor volatile energy generation sites.
As renewables take on a greater share of the country’s energy consumption the UK is on course to meet its renewable targets of 30% renewable generation by 2020. However, converting to this form of power supply is not without difficulties.
To give you an idea of the overall picture, UK emissions fell by 9.1 million tonnes, a year on year 2.4% decrease which was due to an increase in renewable electricity sources. Renewables made up 33% of electricity in 2018 which was up from 29.2% in 2017. Despite this fossil fuels still make up 79.4% of the overall energy supply. The pace of change needs to be accelerated.
Even now, cost is still one of the main barriers to the adoption of renewable energy generation resources. Developed countries like the UK have a mature fossil-fuel infrastructure that has been in existence for over a hundred years. Making the change to a renewable alternative can in many cases be more expensive and involve a much higher initial investment.
The same applies to developing countries where the cost of renewable technology is even more prohibitive.
The UK’s present energy infrastructure was designed to run on fossil fuels is being forced to adapt. The grid is now distributing energy generated from both fossil-fuel and renewable sources.
Recently smart grids which use control and communication in a specific way to counteract the need for costly expansion of existing cable and wire infrastructures have expanded.
Billions of pounds will be spent on Britain’s energy network in the next few decades. Some of this will be required to keep the existing system going and to replace ageing equipment while the creation of a smart grid will also need investment in new technology.
Notably, this requirement has encouraged a pledge by the UK’s leading electricity network operators, including SSE Networks and UKPower Networks. This pledge promises to deliver £17 billion of smart grid infrastructure by 2050.
A key differentiator of smart grids is the integration of renewable energy generation resources. This technology is essential to provide easy integration and reliable service to consumers. A smart grid system is an entirely self-sufficient electricity network system using digital automation technology for monitoring, control and analysis within the supply chain. It improves the communication, automation, and connectivity of the various components of the power network which allows as an example for bulk transmission of power gathered from multiple generation plants.
Technology investments need to be made as operators cannot accurately predict output from renewable sources because unlike fossil fuels, they do not generate energy at a pre-determined level.
The way that wind turbines work illustrates this clearly. Although an operator can estimate from historical data how often the windfarm will generate power consistently it is virtually impossible to make accurate predictions as energy output from a turbine can drop without warning and there is no proven method to precisely determine when output will improve.
The variability of renewable energy sources can affect power supplies in the reverse way by producing surplus energy. If the wind speed was to dramatically increase and the grid was not prepared it may not be able to handle the sudden surge in power from the windfarm which could lead to a power outage.
Reserve power flow, or back feeding, is one method of managing this excess energy.
Back feeding is flow of electrical energy in the reverse direction from its normal flow. For example, back feeding may occur when electrical power is injected into the local power grid from a source other than a utility company generator.
Back feeding isn’t exclusively for renewable sources and occurs regularly on small-scale power grids usually during the middle of the day as residential energy demand is low during this period meaning that some of the generated electricity can be fed back to a transformer through the network.
Because most power generation came from large-scale fossil-fuel sources, which were located on the main network, the power would flow predictably onto smaller systems in the past.
With the number of renewable energy sites increasing as well as microgeneration sites energy volatility is increasing which inevitably leads to more occurrences of back feeding as well as creating a new requirement for energy storage.
More accurate forecasting is needed so that operators can manage supply and demand. Though there is new technology that is already beginning to improve the exactness of predictions by using advanced computer models it is recommended that this is used in combination with real-time monitoring.
Smart grid control software allows operators to manage grid behaviour in real-time which means that the operator can react appropriately should the site begin to generate more or less power than expected.
Obviously, this real-time insight doesn’t change the volatility of renewable generation, but the software can immediately alert an operator when wind speeds increase. By comparing this data with information from the network the software can provide a warning that a surplus of energy is going to occur, and back feeding is required.
Back feeding isn’t always the answer, in some cases the excess energy must be stored. Research by market analyst Aurora Energy Research suggests that in order for the UK to meet its renewable energy targets, an additional 13GW of energy storage will be required to successfully balance the grid.
This presents another big challenge related to the cost of implementation as with other forms of energy technology. Traditionally aside from the water storing methods of hydro-electric plants, electricity grids have little if any method of storing excess power. In fact, Aurora Energy Research’s paper states that deploying energy storage on Britain’s network will require a £6 billion investment.
Being able to store energy plays an important part in creating a flexible grid. If there is more power generated than is required, the excess energy needs to be stored safely to avoid any wastage. If the demand is greater than the energy available, energy storage allows storage facilities to discharge the stored energy back to the grid.
With increasing reliance on renewables, energy storage facilities will be essential buffers for excess power. While there are copious research projects dedicated to the development of energy storage methods, including compressed air, thermal storage and battery storage, these technologies are still largely in their infancy.
Across the continent, there are several successful examples of using batteries to store excess renewable energy. This includes a BMW commissioned battery storage farm in Leipzig, Germany, which is housed on the grounds of its own wind generation site. The site operates using 700 second-life electric vehicle batteries, which are used to house excess wind power before it is fed back into the wider grid.
Without knowledge of when, where, and how much energy is required on the grid, however, battery storage is redundant.
Feeding this energy back to the network requires real-time insight into the state of the gird. Large scale installations, like BMW’s facility in Germany, will use intelligent software to constantly monitor and record demand for power and therefore supply appropriately.
Again, this requires investment from the facility itself but is essential for the creation of a truly smart energy grid.
Transitioning from a traditional energy network to a fully functioning smart grid is incredibly complex. Britain’s ageing infrastructure means that costs maintaining and repairing these facilities are essential, but investments in new technology cannot be overlooked.
A solution to a slow transition could be public sector investment. Governments could provide long-term capital which would balance the low rate of returns renewable projects currently yield.
It is possible that the model used in oil and gas of creating power companies via the public sector and then privatizing them could be repeated in renewable energy.
However, to achieve that with renewable energies, governments must understand that they have a greater value than short-term financial returns.
Renewable energy is growing swiftly but hydrocarbon fossil fuels continue to dominate the global energy mix.
Britain may be capable of generating 100% of its energy supply from clean sources, but until the nation has adopted technologies to efficiently manage, store and distribute this energy, this goal will not come to fruition.