The cost of waiting: modelling three years of “we’ll look at it next year”

Why “next year” feels free, and why it isn’t

Every solar and energy proposal meets the same response at least once: “It makes sense, but let’s revisit it next year.”

It’s rarely a no. More often, it’s a sensible-sounding deferral. Maybe you’re wanting to protect capital, or wait for a quieter quarter. Maybe see what happens with energy prices or simply avoid taking on another project while other priorities are competing for attention.

On the surface, delaying can feel like a safe option. Nothing is spent, no project has to be approved and no installation needs to be planned. The decision can always be revisited later.

The trouble is that delaying is itself a choice that carries a price. It may not appear on a spreadsheet though, which makes it easy to overlook.

It isn’t money that leaves the business as a new cost. It is money the business could have saved but didn’t. That makes it harder to measure, but it’s there nonetheless.

If a solar installation would save £8,000 over the next 12 months, postponing it by a year does not preserve that £8,000 for later. The opportunity disappears. The business buys another year’s worth of grid electricity instead, and when the system is eventually installed, its savings start from that point onwards.

So what does that really mean in practice? Here, we’ll model three consecutive years of “we’ll look at it next year” using the figures from an actual commercial solar project.

The system we’ll model

We’ll use a genuine Hybrid installation: a 64.8 kWp commercial rooftop solar PV system in Ellesmere Port.

The system was designed around a relatively complex commercial roof, with panels divided across eight roof groups to accommodate different roof orientations and shading conditions.

The headline numbers from the proposal were:

• System size: 64.8 kWp
• System cost: £71,944 excluding VAT
• Modelled annual generation: 45,737 kWh
• First-year electricity bill saving: £7,815
• Modelled annual consumption offset: 53%
• Payback period: 7 years and 8 months
• Modelled 20-year net lifetime saving: £211,688

This isn’t an example based on a perfect south-facing warehouse roof, or with unrealistic assumptions baked in. The site had multiple roof orientations and a significant shading factor, yet the economics still worked.

Now imagine two otherwise identical businesses.

Business A approves the project and installs the system.

Business B decides that solar makes sense, but says: “Let’s look at it again next year.”

Then it says the same thing a year later.

And again the year after that.

What has Business B actually lost?

Year one of waiting: roughly £7,800 gone

The first year is the easiest to analyse. Business A installs the solar PV system and starts generating electricity. Instead of buying all of its electricity from the grid, part of the site’s daytime demand is supplied directly by the rooftop array.

Based on the project modelling, that creates approximately £7,815 of electricity bill savings in the first year.

Meanwhile, Business B waits. It’s true that it doesn’t incur the capital cost of the solar system, but it also doesn’t generate any solar electricity. Every kilowatt-hour that the proposed system could have supplied is instead purchased from the grid.

At the end of year one:

Business A has saved approximately £7,815.

Business B has saved £0.

That £7,815 is not sitting somewhere waiting to be recovered when Business B eventually installs solar. It has already been spent on electricity.

That is the first problem with viewing delay as a neutral decision – It isn’t neutral. The business is effectively choosing to continue buying electricity that it already knows it could potentially generate itself.

Year two: the gap keeps growing

Now suppose Business B reaches the following year and solar once again appears on the investment agenda.

The business case still looks sensible, but another project wins the capital budget. Perhaps there’s new machinery to buy, a building refurbishment to complete or uncertainty about trading conditions. The decision is made to defer.

Business A, meanwhile, has entered its second year of solar generation. Using the first-year saving as a simple benchmark, another year adds roughly another £7,800 of avoided electricity costs.

That takes the cumulative difference between the two businesses to around £15,600.

And this is where the cost of delay starts to become more significant.

£7,800 might be dismissed as one year’s missed opportunity. £15,000-plus starts to look more like a meaningful contribution towards the original capital cost of the system.

Year three: more than £23,000 in savings missed

A third year passes. By now, Business A has had approximately three years of lower electricity costs.

On the same simple first-year basis, those savings amount to roughly:

• Year one: £7,815
• Year two: another £7,815
• Year three: another £7,815

That gives a cumulative figure of around £23,445.

In reality, the project’s financial model assumes electricity costs increase over time, so the actual cumulative value of avoided grid electricity could be higher. But even if we deliberately keep the calculation simple and assume no increase whatsoever in annual savings, three years of waiting still costs more than £23,000 – close to a third of the original £71,944 system price.

And unlike an investment in equipment, staff or premises, there is nothing left behind for that money – no asset or additional generation capacity. Business A also misses out on reduced exposure to grid prices.

The payback clock hasn’t been running while you wait

There is another way to look at the same decision.

Our Ellesmere Port system had a modelled payback period of 7 years and 8 months.

For the company that installs immediately, that payback clock starts as soon as the system begins generating.

For the company that waits for three years, it doesn’t.

If the eventual economics of the installation remained broadly similar, the second business hasn’t somehow shortened the payback period by waiting. It has simply moved the starting line three years further into the future.

This matters particularly because commercial solar is a long-life infrastructure investment.

The financial case isn’t usually based on what happens over the next 12 months. It is based on years, and often decades, of electricity generation.

A three-year delay therefore does more than sacrifice three isolated years of savings. It shifts the whole timeline of the investment.

A business that might otherwise have reached payback before year eight is instead only beginning that journey three years later.

Waiting also delays the years after payback

Payback gets a lot of attention when businesses assess solar, but it is only one milestone.

The more important period can be what happens after the capital cost has effectively been recovered through savings.

Once a system reaches payback, the electricity it continues to generate can contribute further net savings for the remainder of its useful operating life, subject to maintenance, performance and the assumptions in the original financial model.

For the Ellesmere Port project, the modelling indicated £211,688 of net lifetime savings over 20 years after the capital cost of the system.

Every year a viable project is delayed pushes that longer-term benefit further away too.

It is therefore worth thinking about solar not simply as:

“Should we spend £71,944 this year?”

but as:

“What happens financially if we leave this roof producing nothing for another year?”

Those are two very different ways of framing the same decision.

“But won’t solar panels be cheaper next year?”

Possibly.

Technology can become cheaper, products improve and supply-chain conditions change. It’s reasonable for a business to wonder whether waiting could produce a better installation for less money.

But a future reduction in system price has to be weighed against the savings surrendered while waiting.

Imagine, for example, that a comparable system became several thousand pounds cheaper after a year.

If the business sacrificed around £7,800 of electricity savings to achieve that reduction, the lower purchase price would need to be significant before delaying actually left the company better off – and there is no guarantee that the overall installed cost will fall anyway.

Solar modules are only one part of a commercial project’s price. The final figure can include inverters, mounting systems, isolators, electrical works, design, access requirements, labour, project management and other installation costs.

Waiting for a theoretical future discount therefore isn’t automatically the same as saving money.

The comparison has to be between the full cost of installing now and the full economic cost of waiting.

“What if electricity gets cheaper?”

This is the other obvious reason to wait.

If grid electricity prices fall substantially, then every kilowatt-hour generated by solar is worth less in avoided electricity costs. That can affect the financial return.

Could wholesale electricity prices fall? Of course. But wholesale energy is only one part of the final bill businesses pay.

Network charges, levies, standing costs and other non-commodity elements also contribute to electricity costs. Cornwall Insight’s Business Energy Cost Forecast has indicated that small industrial firms could still be paying substantially more for electricity in 2026-27 than they did before the energy crisis, while non-commodity costs are expected to represent a growing share of the total bill.

That matters because waiting for wholesale markets to return to previous lows does not necessarily mean the final electricity bill follows them all the way down.

More importantly, a company considering solar doesn’t actually need to predict the exact electricity price three or five years from now.

The relevant question is simpler:

How much electricity are we likely to buy from the grid if we don’t install solar, and what is that likely to cost us compared with generating some of it ourselves?

If the numbers still work under relatively conservative assumptions, betting on dramatically cheaper future electricity may not be a particularly strong reason for indefinite delay.

Doing nothing is still an energy strategy

Businesses are understandably cautious about investment decisions. But it is useful to recognise that keeping the current arrangement is itself a decision.

If a site currently buys close to all of its electricity from the grid, choosing not to install on-site generation means deciding to continue with that model.

That leaves the business exposed to:

• Future electricity price changes
• Network and non-commodity charges
• A greater proportion of consumption being purchased externally
• Less control over long-term energy costs
• Delayed progress towards sustainability or carbon-reduction targets

That may still be the right choice, but the point is that it shouldn’t be treated as the absence of a choice.

The opportunity cost is bigger on larger systems

Our Ellesmere Port example is a 64.8 kWp installation.

For many industrial sites, warehouses, distribution centres and larger commercial properties, the potential system could be considerably larger.

That makes the cost of delay correspondingly bigger.

If another project’s modelling showed potential annual savings of £25,000, then one year of waiting isn’t an £8,000 decision. It could be a £25,000 decision.

If the saving were £50,000 a year, three years of deferral could mean £150,000 of electricity savings sacrificed before considering changes in tariffs or consumption.

This is why the phrase “we’ll revisit it next year” deserves closer examination on large energy projects. The larger the opportunity, the more expensive passive delay can become.

Consumption matters as much as roof size

It is also important not to assume that a large roof automatically means a strong solar business case.

Commercial solar works particularly well when generation can be matched with electricity demand on site.

In the Ellesmere Port model, the business used approximately 86,000 kWh of electricity per year, and the proposed solar array was expected to generate 45,737 kWh.

Of that generation, around 25,457 kWh was expected to be consumed directly on site.

That direct consumption is important because electricity generated and used behind the meter can reduce the amount that needs to be purchased from the grid.

When modelling the cost of delay for another business, Hybrid would therefore look at factors such as:

• Annual electricity consumption
• Daytime demand profile
• Current electricity tariff
• Available roof area
• Roof orientation and pitch
• Shading
• Export potential
• Expected generation
• Future changes in electricity demand

A factory operating throughout daylight hours may have a very different solar opportunity from a property with little daytime consumption, even where the buildings have similarly sized roofs.

Roof constraints don’t automatically destroy the business case

Another common reason for putting solar off is that the site doesn’t look ideal. Perhaps the roof faces several directions, there’s shading, or the available space is broken into awkward sections.

To revisit the Ellesmere Port project, it’s useful precisely because it wasn’t a textbook roof.

The array had to be split across eight separate roof groups, with orientations ranging considerably around the building. The modelling also accounted for a notable shading loss factor.

Yet the proposed system was still forecast to offset around 53% of the site’s annual electricity consumption and achieve a payback period of 7 years and 8 months.

That doesn’t mean every difficult roof will work of course, but it means businesses shouldn’t assume they have to wait for the perfect building, perfect tariff or perfect set of conditions before exploring the opportunity. We endeavour to understand the constraints and model what can realistically be achieved around them.

There are good reasons to wait

None of this means every business should approve solar immediately. There are perfectly sensible reasons to delay a project.

The roof needs replacing

Installing solar onto a roof that is approaching the end of its useful life can create unnecessary cost and disruption later. In this case, coordinating roof works and solar installation may be the better strategy.

The building may be sold or vacated

If the company is likely to leave the property shortly, the investment case needs to reflect that.

The capital has a better use elsewhere

Solar has to compete with every other investment opportunity available to a business. If capital invested in production equipment, recruitment or expansion would produce a substantially greater return, that is a valid consideration.

Electricity demand is about to change

A major new production line, electrification project, EV fleet or operational change could substantially alter consumption. It may make sense to model the future site rather than today’s one.

The project still contains unanswered technical questions

Structural suitability, grid requirements, electrical infrastructure or planning considerations may need to be resolved before a sound investment decision can be made.

If you defer, put a number against the decision

A useful way to make the decision more disciplined is to treat delay as one of the options in the financial model.

Instead of comparing:

Install solar
versus
Do nothing

compare:

Install in 2026
Install in 2027
Install in 2028
Install in 2029

Then calculate the cumulative savings under each scenario.

For our simple Ellesmere Port example, using the first-year saving without any inflation:

That doesn’t automatically mean “install now” is right, but it means the decision maker can see the price of each option.

If waiting a year avoids a major roof replacement problem, £7,815 may be a perfectly reasonable cost to accept. If waiting achieves nothing other than postponing the discussion to the following budget meeting, it’s harder to argue for.

The carbon impact waits too

The financial case is usually the main commercial driver, but the environmental benefits are delayed as well.

The Ellesmere Port system was modelled to avoid approximately 12 tonnes of CO₂ emissions each year.

Three years without the proposed system therefore means three additional years in which those emissions reductions are not being achieved.

For businesses working towards internal carbon-reduction targets, customer sustainability requirements or wider ESG commitments, delay can therefore affect more than energy expenditure.

Again, whether that matters enough to justify investment depends on the company – but it is another consequence that should be visible when the decision is made.

The real question is what the delay buys you

This is ultimately the most useful way to think about it. Waiting isn’t necessarily wrong, but if waiting costs approximately £8,000 a year in forgone savings, what does the business receive in return?

Perhaps it receives:

• Time to replace the roof properly
• A stronger cash position
• Certainty over a forthcoming site expansion
• Better information about future electricity demand
• The opportunity to coordinate solar with battery storage or EV charging
• Capital for another project with a stronger immediate return

Those can all be rational trades.

But if the answer is simply: “Nothing really. We’ll just look at it again later.”, then the business is effectively paying thousands of pounds for indecision.

A better question than: “Can we wait another year?” is: “What will waiting another year cost us, and is what we’re gaining by waiting worth more than that?”

Hybrid Asset Solutions can model this using your site’s actual electricity consumption, tariff, roof conditions and potential solar generation. That gives you a clear comparison between installing now and delaying by one, two or three years, so the decision is based on the numbers rather than becoming another automatic “we’ll look at it next year.”