THE DISTRIBUTED ENERGY SHOW, 12TH & 13TH MARCH 2025, NEC, BIRMINGHAM

10/11/2021

Sponsor Spotlight: SSE Energy Solutions

Affordable Net Zero Targets See V2G Drive Distributed Energy Resources Adoption

The path to the UK successfully achieving its Net Zero emissions targets in an affordable manner has many milestones along the way: policy changes, low-carbon technologies and grid up-grade requirements are all essential factors.

To meet Net Zero goals the UK’s energy mix will require greater wind and solar penetration. To make that happen energy storage will have to track renewables’ growth to ensure continuity of supply when the wind stops blowing and the sun stops shining.

From generation to distribution sectors, renewables (both onsite generation and co-generation), and energy storage (microgrids, virtual power plants and kW-MW-scale stand-alone systems) are key elements to decarbonising power and heat. Today, both are being deployed independently or as a collective solution, depending on the location.

The level of activity in organisations tackling decarbonisation has increased, however, the pace of deployment is an on-going challenge with various elements contributing to the length of time it takes from customer engagement to ‘energisation’, said Ross McClory, Head Of Business Development Distributed Energy and Private Networks at SSE Energy Solutions.

SSE Energy Solutions provides localised integrated solutions to generate and store clean energy. Its goal is to accelerate business’ transition to Net Zero and create a more resilient and sustainable energy system by investing in, and building and connecting localised infrastructure. The company has the capability to provide resilience and flexibility to the power supply, achieving carbon reduction in the most cost-effective manner for all consumers.

The company works with relevant Distributed Network Operators (DNO) on specific projects, and with the National Grid to identify ways to optimise the scale of the solutions identified within a geographical area.

“Collaboration within industry as well as with local and national governments is key to success, and we would welcome further conversations across industry,” said McClory. The company’s Distributed Energy Solutions business utilises an approach known as ‘Whole System Thinking’. This approach enables businesses to tackle the challenge of managing private networks, decarbonising heat, the transition to electric vehicles (EV) and integrating renewable generation into existing or new infrastructure while retaining their key goals, which include: decarbonisation of operations, improving resilience and achieving cost sustainability.

The ‘Whole System Thinking’ solution combines data analytics tools and digital technologies to coordinate and manage energy in the most flexible, energy-efficient and cost-effective way to drive the long-term performance of energy assets.

The company recognises its business clients are facing a set of key challenges and its portfolio of energy assets incorporates advanced technologies with the goal of decarbonisation. These include: flexible generation and storage, and EV charging.

V2G technology

With the UK set to ban new sales of petrol and diesel internal combustion engines in 2030, the drive to increase the percentage of battery-EV (BEV) and plug-in hybrid EV (PHEV) vehicles in the UK’s combined fleet has begun.

A typical EV has a 30kWh battery, enough to power an average UK home. Often this power source is only utilised when driving, so what better demonstration of a decentralised energy system than linking thousands of customer-owned energy-storage devices to provide stability to the grid. The thinking is that if EV batteries are made available then the pressure on public bodies to deploy grid-scale energy storage systems in their transition to Net Zero can be eased.

While the role to decarbonise power could be filled with batteries, using EVs allows the use of existing assets more efficiently, a key tenet of the Net Zero transition, said Jennifer Yates, Project Development Engineer SSE Energy Solutions.

Vehicle to grid (V2G) technology discharges stored energy from the EV’s battery pack to the grid— similar to a stationary battery— to deliver grid services ranging from demand response and voltage regulation to distribution-level services.

SSE Energy Solution’s Bus2Grid project is a first of a kind large-scale, multi-megawatt, V2G demonstration that enables 28 e-buses to provide bi-directional charging connected to an aggregation platform, which enables the batteries to interact with the energy system. The project is hosted at Northumberland Park, the UK’s largest electric bus depot, and is one of nine depots electrified by SSE Energy Solutions.

Once connected to a charger, each bus’ charger management system (CMS) reads the battery’s state of charge, with the battery’s availability update relayed to the fleet management system BAFAS. This information is then relayed to an energy router, which is also monitoring the site’s power flows through metering points.

If an event— such as a requirement for frequency response— happens and SSE Energy Solutions makes the decision to trade the power a signal is sent to the energy router, which communicates the decision back to the buses via BAFAS and CMS.

This all takes places within the context of operational restraints such as allowing the buses to recharge after a full day’s usage and ensuring the buses are fully charged for the next day of work. Revenue sharing models vary according to the business model of each V2G project.

Challenges of V2G rollout

The primary purpose of an EV is transportation, and concerns over V2G interfering with this are unlikely to go away until it is proven over multiple projects/applications. If any V2G roll out is to be successful it’s critically important it does not affect the operations of the vehicle, such as its battery’s cycle-life.

In the Bus2Grid project, a built in safety limit prevents the battery from discharging below a minimum state-of-charge in order to protect and preserve the battery’s cycle life. SSE Energy Solutions does not expect to see a significant impact on battery life over the course of the project.

“While battery degradation will occur with an EV, research published by the European Commission suggests that if V2G operations are optimised correctly then there should not be a negative effect and potentially there may even be a positive effect, similar to that seen via smart charging. These results should be validated via real-world testing in the long term, but it is promising,” said Yates.

New challenges

Bus2Grid’s stakeholders are: bus manufacturer BYD; DNO UK Power Network; academic partner University of Leeds; SSE Energy Solutions with energy optimisation technology provider Origami; and bus operator Go-Ahead London. Combining multi-sector experience to make the project a reality introduced new challenges.

An important learning curve was the energy companies and bus manufacturers— not traditional project partners—developing a common understanding over the course of the venture.

Additional learning curves related to hardware and software development, and the communication between systems. The Bus2Grid project required development of bespoke hardware not initially designed to provide discharge capability, which presented a regulation challenge with achieving G99 certification.

“While we believe that we have overcome that now, and can anticipate for future projects, there is still an element of difficulty involved in fulfilling requirements which are not applicable for conventional EV projects,” said Yates.

Interoperability between different models of chargers and vehicles also needs to be addressed. This issue was easily solved in the Bus2Grid project by using BYD vehicles and chargers; but on a countrywide scale, marrying the vehicle to the charger may not be possible, and certain vehicles will not work with certain chargers. While this is widely acknowledged as an issue there is no standardisation across the industry to solve it.

However, international standards like ISO 15118 are being introduced that outline the digital communication protocol that an EV and charging station should use to recharge the EV’s high-voltage battery. But, “there is still work to be done”, says Yates.

The cost difference between a V2G and an EV set up is also significant, but costs are expected to fall as economies of scale come into play.

Another issue to consider is legacy infrastructure, with not all parts of the network suitable for generation connection without reinforcement or additional work by the DNO and potential outages to be managed.

“Power may also be provided at a time it is not needed; for example in the evening peak when energy demand is high the buses will be out on routes and not available for discharge, however later on at night, when demand falls, the buses will be available for discharge,” said Yates.

Important lessons from the Bus2Grid project included: the importance of alignment of duty cycles to optimal energy market periods; local network conditions; asset capacity and suitability and fleet size and availability. All key factors that influence each other to make a successful V2G project.

Business as usual V2G will require longer term understanding and modelling and there is still significant work to be done before it becomes standard with all EVs. 

Business as usual

With an increase in EV sales forecast, there is a promising future for V2G opportunities. However, the uptake of the technology depends on the engagement of the customer— their motivation for choosing an EV and their usage patterns— and on manufacturer support and engagement in developing hardware and software for V2G applications.

With the industry keen to cooperate together to ensure success, recent policies to support Net Zero— including the recent UK government consultation on V2X technology— show the industry’s first steps on the path to decarbonisation are moving in the right direction.

Find out more about SSE Energy Solutions: https://www.sseenergysolutions.co.uk/