Understanding Behind-the-Meter and Front-of-Meter with Joulen’s Jess Fletcher 

In a rapidly evolving energy landscape – and with key decarbonisation targets on the horizon, Joulen’s Electrical Engineer Jessica Fletcher explains what happens on each side of the ‘meter’ and how these distinct systems impact our clean energy transition.

Q: Firstly, can you explain the key differences between Behind-the-Meter and Front-of-Meter?

Jess: Behind-the-Meter (BtM) is all about energy systems installed at sites with existing demand. Think of a house, an office, or a factory already connected to the electricity network. The energy system, such as rooftop solar or battery storage, is situated behind the point where the distribution network operator (DNO) delivers electricity, immediately after the meter. These systems primarily serve the property’s own energy needs, and are limited by what the DNO allows them to use. It’s a practical, on-site setup focused on self-consumption or reducing grid reliance.

On the other hand, Front-of-Meter (FoM) refers to greenfield sites, typically a plain site with no pre-existing infrastructure. These sites are built with the sole intention of providing generation and storage, such as gas turbines, wind turbines, solar farms, battery storage, or sometimes a combination of these. They aren’t tied to any local energy demand. Instead, they produce power for the grid or provide stabilising services such as frequency or voltage regulation. Companies often develop these sites to support the broader energy market rather than directly serving on-site needs.

The main difference is, therefore, generating power for your own use (BtM) compared to producing energy for everyone else (FoM).

Q: Where does energy optimisation fit into these two systems? 

Jess: So, for a behind-the-meter site, optimisation is incredibly helpful in lowering the costs for the client. It prioritises the self-use of the energy produced, helping to keep business and housing costs low. If there is any excess power, it can be exported to the grid and generate additional income. However, historically, the primary purpose has been to supply businesses, factories, or households and keep costs low for the client in this way.

Conversely, a front-of-the-meter site’s purpose is to provide power to customers and generate revenue. Utilising optimisation here, therefore, ensures that the asset earns as much as possible by participating in energy markets. It involves bidding into the correct markets or buying at the best rate so that you can store energy and then sell it at the best price. It will also determine which market is most beneficial for that asset to participate in, such as the capacity market, dynamic containment, or balancing services. It can make sure that we have enough stored in the battery already, or we have sufficient solar coming into the battery that day to meet those requirements. 

So, for energy optimisation, the key differences are that BtM optimisation helps save money, while FoM optimisation helps make money. However, changes in the energy market mean that this gap is starting to close. For example, here at Joulen, our AI software PARIS supports households and businesses not only to generate their own power, but also sell excess capacity to the grid, meaning that BtM generation can also generate income, too. 

Q: What challenges do people and businesses face in participating in energy markets?

Jess: We’re seeing more residential and factory BtM systems come online, which is excellent for green energy adoption. However, the challenges are that homes and businesses have relatively few resources to invest in clean installations. Grants and incentives help, but they don’t always cover the full cost. Currently, there’s not enough financial support to propel the adoption of green energy at the residential or business level.

Conversely, FoM players are making huge amounts of money by competing in the energy markets. Behind-the-meter systems, like those in homes or medium-sized businesses, often can’t join these markets because the entry requirements are so high. Competing in those markets requires at least one megawatt of capacity, which a medium-sized business simply doesn’t need. That makes it hard for them to participate.

So, we end up with a mismatch. There’s a lot of behind-the-meter generation coming online, but it can’t be used effectively for grid services. Meanwhile, front-of-the-meter players are generating and profiting, taking money from the grid without the same constraints.

Then, there’s also the grid infrastructure challenge. FoM companies can be strategic, choosing sites where they know grid approvals will be easier and where export capacity will meet their needs. But for BtM systems with a fixed location, if the grid in their area is outdated or overloaded, they’re unable to participate in the same way. Our current situation is that the grid infrastructure hasn’t been updated quickly enough to allow many homes and businesses to take part. 

Joulen recently earned VTP (Virtual Trading Party) accreditation. How will this help overcome these challenges?

We’re all thrilled with our new VTP accreditation, which will open doors for more people and businesses to participate in the UK’s energy market. As a VTP, our PARIS software connects and manages distributed BtM assets – like solar, batteries, and EV chargers – and aggregates them to overcome the one-megawatt participation threshold. 

This also strengthens the incentive for households and companies to invest in clean energy, as there are now greater financial benefits to be gained. Ultimately, this will help accelerate efforts toward decarbonisation while democratising our energy system. This is such an important, positive step in the clean energy transition.

Where do BtM systems fit into our 2030 target of 100% clean electricity?

Jess: Installing more BtM distributed generation will certainly help reach 100% clean electricity by 2030. While traditional, centralised generation remains important, empowering more and more people to participate in our energy market will only accelerate the transition.

The UK needs to act quickly and innovate if we are serious about meeting our clean energy targets. Take the Government’s Great British Energy initiative. It’s a fantastic idea, but how long will it take to actually set up? And what impact will it have on our current challenges?

The National Grid has sent a clear message that critical decisions must be made within the next 18 months to develop bold, actionable plans, otherwise, the 2030 target will slip through our fingers. Last year, we published our Better Battery Strategy, outlining actionable steps to promote behind-the-meter storage at scale, turning homes and businesses into energy assets and central players in the clean transition. For example, the government must enable access to all energy markets across the fully distributed energy system, including residential homes and businesses. It can also mandate that every new home built must have renewable and battery storage systems already in place, and introduce tax incentives to encourage investment in these systems.

These policies would not only help democratise and decarbonise our electricity system, but most importantly, they can do this very quickly. These BtM systems can be installed significantly faster than new FoM generation sites, providing the UK with the speed and flexibility it urgently needs for the transition.

You can download and read Joulen’s Better Battery Strategy here, and more on our VTP certification here. 

Meet Jess Fletcher

Jess is Joulen’s Electrical Engineer, specialising in project design and consultancy. One of her key projects has been the design and construction of the Metro device, Joulen’s innovative interfacing solution that enables Joulen to interface with any battery. Jess has always been passionate about decarbonisation and renewable energy, driven by a commitment to advancing sustainable engineering solutions.