The UK’s energy system is being rebuilt and grid reinforcement, renewable integration and accelerating electrification are reshaping what sits behind the electricity bill. An increasing share of cost is now driven by regulated, infrastructure-linked charges that are rising steadily as the system modernises. 

For organisations exploring or investing in on-site solar, this shift changes the strategic context. Solar can reduce exposure to wholesale price swings and help meet sustainability targets but now has an increasing role to play in reshaping how much electricity is imported from the grid, and therefore how much of that evolving cost structure an organisation is exposed to. 

In this three-part series, we examine how non-commodity electricity charges are transforming the financial landscape, what that means for the long-term case for on-site generation, and how organisations can design a more resilient and commercially grounded energy strategy. 

PART ONE | PART TWO | PART THREE

Behind the bill: Which non-commodity charges can solar influence? 

In part one, we looked at how the UK energy market is shifting from short-term volatility to long-term structural inflation. An increasing share of electricity costs is now driven by regulated and infrastructure-linked charges: non-commodity charges. 

Next, we need to go behind the bill to find out what non-commodity charges are, how they are applied, and crucially, where on-site solar can make a meaningful difference. 

Beyond the unit rate 

Most organisations still base energy conversations around pence per kilowatt hour. But that figure only tells part of the story. 

For many medium and large electricity users, more than half of the total bill now sits outside the wholesale amount. These non-commodity charges fund the operation, maintenance and transformation of the UK’s energy system. 

They include: 
– Transmission Network Use of System (TNUoS) – funding the high-voltage transmission network that moves power across the country,
– Distribution Use of System (DUoS) – covering regional networks that deliver electricity to sites,
– Balancing Services Use of System (BSUoS) – maintaining real-time supply and demand balance,
– Capacity Market Levy – ensuring sufficient generation is available during peak demand,
– Renewables Obligation (RO) and Contracts for Difference (CfD) – supporting renewable generation,
– Nuclear Regulated Asset Base (RAB) charges – funding new nuclear infrastructure.

These are not arbitrary add-ons; they are the mechanism through which the UK funds grid reinforcement, renewable integration and energy security. 

They are also largely unavoidable, but there are still ways to navigate and mitigate their impact. 

How non-commodity charges are applied 

To understand where solar fits, it helps to understand how these costs appear on the bill. 

Broadly, non-commodity charges fall into three categories: 
1. Consumption-based charges – Applied per kWh consumed from the grid i.e. the more electricity imported, the more you pay.
2. Demand-based charges – As they are linked to peak usage or capacity requirements, these can be influenced by how and when electricity is used.
3. Fixed or standing charges – Applied regardless of usage and therefore generally unavoidable.

While not every charge is directly controllable, some are linked, either fully or partially, to imported electricity volumes and peak demand times. This is where on-site generation becomes commercially relevant. 

Where solar makes a difference

On-site generation through solar primarily reduces the amount of electricity you need to import from the grid. Every kWh generated and consumed on-site is a kWh not imported from the network, which directly lowers exposure to consumption-based elements of: 

– DUoS charges 
– BSUoS costs 
– Certain policy levies applied per imported unit 

That also means as non-commodity charges rise over time, the value of avoided grid imports compounds. 

For electricity-intensive sites operating during daylight hours, the alignment between solar generation and demand can be significant. Manufacturing facilities, logistics hubs, retail sites and distribution centres often have strong daytime load profiles that maximise self-consumption. 

The higher the proportion of on-site generation consumed directly, the greater the reduction in exposure to variable non-commodity charges. 

The demand and timing levers  

Solar primarily reduces the volume of electricity imported from the grid. But cost exposure is also shaped by timing and peak demand. Network costs in particular are sensitive to demand spikes and system stress windows. 

If solar generation coincides with periods of high site load, it can: 
– Reduce peak import levels,
– Lower demand-related network charges,
– Ease exposure during high-cost periods.

However, solar generation is naturally linked to daylight hours, so this is where battery storage (and tariff optimisation) becomes strategically important, by introducing control over timing. 

We’ll look at this in more detail in part three. 

What solar cannot do

It is important to be clear that an integrated solar system does not eliminate all non-commodity charges. 

Fixed standing charges will still apply, and certain policy costs may be embedded regardless of consumption profile. Transmission-related costs can also be complex and partially fixed. 

However, reducing total grid import reduces exposure to the fastest-rising elements of the bill, so in a structural inflation environment, lowering exposure can have a significant commercial impact. 

Turning transparency into control 

Forecasts indicate that several regulated components of electricity costs are set to rise over the coming years as new infrastructure and policy mechanisms come online. Energy cost management is no longer just about negotiating the right contract; it’s about reshaping how much electricity you purchase from the grid in the first place. 

Organisations that rely entirely on imported power will remain fully exposed to regulated escalation, but by generating a proportion on-site introduces a level of insulation and predictability into your cost base. 

Understanding the bill is the first step. The next is deciding how much exposure your organisation is prepared to carry. Questions worth asking include: 

– What proportion of our electricity bill is now non-commodity? 
– How much of that is linked to imported volume or demand? 
– What percentage of our load profile could realistically be met by on-site solar? 
– How would reducing grid import reshape our long-term cost exposure? 

These might seem like technical considerations, but they are commercial and strategic ones. Solar shouldn’t be seen as simply a sustainability investment, but part of a broader response to a changing cost structure. 

In the final part of this series, we will explore how solar, storage and wider energy strategy can be designed together to move from passive exposure to active management, and how organisations can stack solutions to help balance the energy trilemma at the same time.