Commercial Solar Finance Academy Lesson Selection
Finance Directors Commercial Solar Guide
Board Level Business Case Example
Commercial Solar Investment Checklist
Making smarter Energy Investment decisions
Executive Summary
For many UK businesses, electricity is now one of the largest uncontrollable operating costs.
Unlike labour, raw materials or insurance, there are very few opportunities to reduce electricity consumption without affecting business operations. Manufacturing facilities, warehouses, offices, schools, hospitals and distribution centres all rely on electricity to function.
The question for many Finance Directors is no longer “Should we invest in solar?”
It has become:
"Can we continue to rely entirely on buying electricity from the grid?"
Commercial solar provides businesses with an opportunity to reduce operating costs, improve cash flow, create a productive business asset and reduce exposure to future energy price increases.
Investing in commercial solar panels enables organisations to generate their own electricity, reducing reliance on the grid while creating a long-term business asset capable of delivering financial returns for decades. Unlike many capital projects, a commercial solar installation begins delivering measurable financial benefits from the day it is commissioned.
When properly designed, a solar PV system becomes an asset capable of generating electricity for more than thirty years, producing ongoing savings that improve the financial performance of the business long after the initial investment has been recovered.
This guide explains the financial principles behind commercial solar and how Finance Directors can assess the investment using the same financial metrics applied to any other capital project.
Why Finance Directors Are Looking at Commercial Solar
Historically, commercial solar was viewed as an environmental initiative. Today, it is increasingly viewed as a financial decision.
The reasons are straightforward.
Businesses face:
- Increasing electricity costs
- Greater pressure on operating margins
- ESG expectations from customers and investors
- Carbon reporting requirements
- Pressure to improve resilience
Commercial solar addresses each of these challenges while providing a measurable financial return. For many organisations, it is now considered alongside other capital investments such as new production equipment, warehouse automation or manufacturing improvements.
Electricity Is No Longer Just an Overhead
Historically, commercial solar was viewed as an environmental initiative. Today, it is increasingly viewed as a financial decision.
The reasons are straightforward.
Businesses face:
- Increasing electricity costs
- Greater pressure on operating margins
- ESG expectations from customers and investors
- Carbon reporting requirements
- Pressure to improve resilience
Commercial solar addresses each of these challenges while providing a measurable financial return. For many organisations, it is now considered alongside other capital investments such as new production equipment, warehouse automation or manufacturing improvements.
"Can part of this ongoing expense become an investment instead?"
This is where commercial solar changes the conversation.
The Cost of Doing Nothing
One of the most common mistakes when assessing commercial solar is comparing the investment against spending nothing.
In reality, doing nothing still has a cost.
If your organisation currently spends £250,000 each year on electricity, that expenditure will continue whether you invest in solar or not.
Every month:
- Electricity is purchased.
- It is consumed.
- The invoice is paid.
- The process repeats.
None of that expenditure creates a business asset.
None of it increases the value of the organisation.
None of it provides protection against future electricity price increases.
Installing solar panels on your business can change that model.
Instead of purchasing every unit of electricity from the grid, the business begins generating a proportion of its own energy.
The result is not free electricity.
The result is replacing part of an unavoidable operating expense with a productive business asset.
Energy Spend Versus Asset Creation
Every Finance Director understands the difference between expenditure and investment.
Operational expenditure keeps the business running.
Capital investment improves the business.
Commercial solar sits firmly within the second category.
Rather than paying for electricity indefinitely, part of that ongoing expenditure is redirected into an asset capable of producing electricity for decades.
This changes the financial discussion considerably.
Instead of asking:
“Can we afford solar?”
Many organisations begin asking:
“Can we afford to keep buying all of our electricity from the grid?”
Commercial Solar as a Balance Sheet Asset
Unlike monthly electricity bills, which pass directly through the Profit & Loss account as operating expenditure, a commercial solar installation is typically treated as a capital investment.
The installation becomes a long-term asset recorded on the balance sheet, subject to the organisation’s accounting policies and applicable accounting standards.
This distinction is significant.
Electricity purchased from the grid provides value only for the period in which it is consumed.
A solar PV installation continues producing value for many years.
The business owns infrastructure capable of generating electricity every working day.
While the accounting treatment will vary between organisations, many Finance Directors view commercial solar as converting part of an unavoidable operating expense into an income-generating business asset.
Professional accounting advice should always be sought regarding capitalisation, depreciation and tax treatment.
Cash Flow Rather Than Cost
One of the reasons commercial solar has become increasingly attractive is its effect on cash flow.
Many funding solutions allow organisations to spread the investment over several years.
Meanwhile, the solar installation begins reducing electricity purchases immediately after commissioning.
For some organisations, the reduction in electricity costs can offset a significant proportion of finance repayments.
The result is improved cash flow compared with continuing to purchase all electricity from the grid.
Every project is different.
This is why Energy Gain models each proposal individually rather than relying upon industry averages.
Energy Gain Expert Insight
Every commercial proposal begins with understanding how your business consumes electricity.
Rather than estimating savings using industry benchmarks, Energy Gain analyses your electricity bills, half-hourly consumption data, tariff information and future energy price assumptions.
This enables us to model projected cash flow, annual savings and long-term financial performance based on the way your business actually operates.
Return on Investment (ROI)
Commercial solar should be assessed in the same way as any other capital investment.
The objective is not simply to recover the initial expenditure.
The objective is to create value.
Return on Investment measures the financial benefit generated by the installation compared with the capital invested.
The strongest returns are generally achieved where:
- Electricity demand is high.
- Most electricity is used during daylight hours.
- Grid electricity prices are relatively expensive.
- The system is correctly sized.
This is why understanding electricity consumption is far more important than simply measuring roof area.
Why the Biggest System Isn't Always the Best Investment
One of the most common misconceptions is that every available roof should be covered with solar panels. Every commercial rooftop solar installation should be designed around the way a business consumes electricity rather than simply maximising the number of solar panels installed. Optimising self-consumption often delivers a stronger financial return than installing the largest possible system.
From a financial perspective, this is not always the correct answer. If a significant proportion of electricity generated is exported rather than consumed on site, the financial return may reduce.
Energy Gain therefore sizes systems using half-hourly electricity data to maximise self-consumption.
Sometimes this means recommending a smaller system than the customer originally expected.
Although this may reduce installed capacity, it often improves:
- Return on Investment
- Cash flow
- Net Present Value
- Internal Rate of Return
The objective is not to install the largest system.
The objective is to create the strongest business case.
Payback Period
Payback remains one of the simplest financial measures.
It answers one straightforward question:
How long will it take for the investment to recover its original cost?
While useful, payback should never be considered in isolation.
A solar installation continues generating electricity for many years after it has paid for itself.
Two projects with similar payback periods may produce very different lifetime financial returns.
For this reason, Energy Gain also considers Net Present Value, Internal Rate of Return and projected lifetime savings when assessing commercial solar investments.
Project Example
Sector: Motor Industry
| Item | Value |
| Capital Investment | £128,00 |
| System Size | 200 KWp |
| Annual Generation | 156,000 KWh |
| Annual Electricity Spend | £145.101 |
| Estimated Annual Saving | £30,576 |
| Estimated Capital Allowances | £32,000 |
| Simple Payback | 3.1 Years |
| Net Present Value | £330,327k |
| Internal Rate of Return | 31% |
| Projected Lifetime Savings | £991,101 |
Lifetime Return on Investment £901,898
Levelised Cost of Energy 3.71p p/KWh
Questions Every Finance Director Should Ask
Before approving a commercial solar investment, consider asking:
- How have electricity price forecasts been calculated?
- Is the system sized using actual half-hourly electricity data?
- What percentage of electricity will be consumed on site?
- What assumptions have been used?
- What happens if electricity prices change?
- Can the system be expanded in the future?
- What are the projected lifetime savings?
- How does this investment compare with alternative capital projects?
- Is the installation RC62 compliant?
The answers to these questions form the foundation of a robust investment decision.
Looking Beyond Payback
Payback is often the first figure people ask for, but it should not be the only measure used when evaluating a commercial solar investment.
A project that pays back in five years may continue generating savings for another 25 years or more.
Finance Directors should therefore assess the entire financial life of the asset rather than focusing solely on when the original investment is recovered.
Commercial solar is unusual because once installed, the “fuel” is free. The ongoing financial benefit comes from reducing the amount of electricity purchased from the grid, creating savings year after year.
Net Present Value (NPV)
One of the most widely used investment appraisal techniques is Net Present Value (NPV).
NPV recognises that money received in the future is worth less than money received today. By discounting future cash flows back to today’s value, NPV measures whether an investment creates wealth for the business.
A positive Net Present Value indicates that the projected financial benefits exceed the initial investment after allowing for the cost of capital. For commercial solar, NPV is often particularly attractive because the asset continues producing savings long after the initial investment has been recovered.
Unlike many capital projects, the financial benefits continue throughout the operational life of the system.
Why Finance Directors Value NPV
NPV allows commercial solar to be compared with other investment opportunities using a consistent financial methodology.
Rather than simply asking:
“How quickly does it pay back?”
Finance Directors can ask:
“How much value does this investment create over its lifetime?”
Energy Gain Expert Insight
Every Energy Gain proposal includes projected cashflows over the life of the system. This enables us to calculate Net Present Value using realistic assumptions based on your electricity consumption, energy tariffs and future price forecasts.
Internal Rate of Return (IRR)
Internal Rate of Return (IRR) is another widely recognised investment measure. Rather than expressing value in pounds, IRR expresses the investment as an annual percentage return.
This allows commercial solar to be compared with other capital investments competing for available funding.
For many organisations, IRR forms part of the internal approval process alongside Payback and Net Present Value.
Why IRR Matters
Different projects often require different levels of investment.
IRR enables businesses to compare those opportunities using a common financial metric.
Commercial solar frequently performs well because savings begin immediately after commissioning and continue over a long operational life.
Lifetime Financial Performance
Commercial solar should not be viewed as a five-year investment.
It is more appropriate to assess performance over the expected life of the asset.
During this period the system may deliver:
- Reduced electricity costs
- Protection against energy inflation
- Lower operating expenditure
- Improved business resilience
- Long-term carbon reduction
The majority of financial benefits are often realised after the original investment has already been recovered.
Understanding Risk
Every investment carries risk.
Commercial solar is no different.
However, many of the risks associated with commercial solar can be identified and managed during the design stage.
These include:
- Electricity price assumptions
- Future energy consumption
- Equipment performance
- Building alterations
- Grid constraints
- Maintenance requirements
Using realistic assumptions rather than optimistic projections helps produce a robust investment case.
Energy Gain Expert Insight
Our financial models are based on actual electricity consumption, realistic generation forecasts and conservative assumptions. We would rather under-promise and over-deliver than rely on unrealistic savings projections.
Sensitivity Analysis
No one can predict future electricity prices with certainty.
For this reason, Energy Gain recommends assessing a project under different scenarios.
For example:
| Scenario 1 | Conservative | Expected | Higher Electricity Price Growth |
| Scenario 2 | Conservative | Expected | Higher Future Energy Demand |
| Scenario 3 | Conservative | Expected | Higher Solar Generation Predictions |
This allows decision-makers to understand how different market conditions may affect the investment over time. The software is highly interactive, allowing real time analysis.
Capital Allowances
Commercial solar may qualify for capital allowances depending on current legislation and the circumstances of the business.
Many organisations also ask whether the installation qualifies as plant and machinery for tax purposes.
As tax legislation changes regularly, businesses should always seek advice from their accountant or tax adviser before making an investment decision.
Energy Gain can provide the technical information required to support those discussions
Funding the Investment
Commercial solar can be funded in several ways.
Options may include:
- Outright purchase
- Asset finance
- Hire purchase
- Finance lease
- Power Purchase Agreement (PPA)
The most suitable option depends on:
- Cash reserves
- Borrowing strategy
- Investment priorities
- Ownership objectives
- Long-term business plans
There is no single solution that suits every organisation.
Building the Business Case
A successful business case should answer three questions.
Will it reduce operating costs?
Detailed modelling should demonstrate projected annual savings.
Does it represent a good investment?
ROI, Payback, NPV and IRR should be considered together rather than individually.
Does it support the wider business strategy?
Commercial solar can contribute towards:
- Net Zero objectives
- ESG commitments
- Carbon reduction
- Energy resilience
- Cost certainty
Energy Gain's Financial Modelling
Every project begins with a detailed commercial solar feasibility study. This assesses electricity consumption, roof suitability, structural capacity, grid connection requirements and financial viability before any system is recommended. Every Energy Gain proposal is built around your business.
Our financial assessment typically includes:
- Energy bill review
- Half-hourly electricity analysis
- Solar generation modelling
- Self-consumption analysis
- Export analysis
- Current tariff review
- Future electricity price assumptions
- Annual savings
- Cashflow forecasting
- Payback calculation
- Net Present Value
- Internal Rate of Return
- Lifetime savings
- Carbon reduction
This enables Finance Directors to compare commercial solar with any other capital investment using familiar financial measures.
Board Approval Checklist
Before approving a commercial solar investment, consider the following:
☐ Have we analysed our electricity consumption?
☐ Is the system correctly sized?
☐ Have we reviewed funding options?
☐ Have we considered tax implications?
☐ Have we reviewed the financial assumptions?
☐ Have we assessed long-term savings?
☐ Has Net Present Value been calculated?
☐ Has Internal Rate of Return been calculated?
☐ Have we considered future business growth?
☐ Have we selected an experienced commercial installer?
FAQs
Is commercial solar a capital investment?
Yes. Commercial solar is generally treated as a capital investment, although the accounting treatment will depend on your organisation’s policies and professional advice.
Why doesn't Energy Gain simply recommend the largest system
Because the largest system doesn’t always deliver the strongest financial return. We size systems to maximise long-term value rather than installed capacity.
How accurate are financial forecasts?
Forecasts are based on your actual electricity consumption together with reasonable assumptions about future energy prices and system performance.
Should we finance or purchase outright?
The answer depends on your cash flow, investment strategy and funding objectives. Both options can provide attractive financial returns.
Can commercial solar improve cash flow?
Many businesses experience lower electricity costs immediately after installation. Depending on the funding structure, these savings may offset a proportion of finance repayments.
What information does Energy Gain require?
We typically request electricity bills, half-hourly electricity data and details of your business objectives. This allows us to prepare a tailored financial assessment.
Key Takeaways
Commercial solar should be assessed in the same way as any other strategic investment.
While reducing carbon emissions is an important benefit, the financial case is often driven by lower operating costs, improved cash flow and long-term value creation.
By combining engineering expertise with advanced financial modelling, Energy Gain enables Finance Directors to evaluate commercial solar using recognised investment appraisal techniques such as Payback, Net Present Value and Internal Rate of Return.
The result is a robust business case based on your organisation’s actual energy consumption, helping you make informed investment decisions with confidence.
Commercial Solar Finance Academy Lesson Selection
Finance Directors Commercial Solar Guide
Board Level Business Case Example
Commercial Solar Investment Checklist
