Selling solar is relatively straightforward. You show the client how much:
- Electricity their sites use
- Grid power your proposed panels will replace
- Switching to solar power will save in grid power costs
- Revenue they can expect when they export power back to the grid
The maths are visible and the savings story is simple.
Selling batteries is different and the calculation far more complicated. You have to show the client:
- The site's actual tariff structure
- The spread between cheap and expensive periods
- Pass-through charges like DUoS
- The demand pattern through the day
- The control strategy the battery will actually follow
What makes selling solar-plus-battery harder still is that CFOs, FDs and finance leads want to stress-test the figures. Expect everything you present to undergo real scrutiny.
Walk in with a static proposal and you'll spend most of the meeting fielding questions on tariff assumptions, battery behaviour and downside scenarios you can't prove on the spot.
Without interactive software, your rep has to get head office to rework the numbers to cover every scenario the client wants to see. Momentum is lost and they begin talking to your competitors in the meantime.
Walk in with interactive software that lets the head of finance change the inputs and test the scenarios themselves, and you're much more likely to move the decision forward and secure a high place on their shortlist.
This article explains what to look for in commercial solar proposal software, where most tools fall short on batteries, and how the right one helps you close more work.
What finance leads want to see, and why most tools can't show it
Finance leads want to dig into the following when examining your proposal:
- Tariff structure: what they pay per unit, when the expensive periods are, and how much extra they'll pay for usage spikes above a certain level
- Export: what surplus power is worth when it goes back to the grid
- Grid and planning: whether the local network can handle the extra generation, whether there are limits on how much can be exported, and whether any approvals are needed before work starts
- Payback: how long the savings take to cover the cost of the installation, and what assumptions that number is built on
Today's boards are genuinely interested in the possibilities commercial battery storage offers, and that makes this a real sales opportunity. To prove the worth of your proposal, you need to let them pressure-test the numbers themselves. That way, you demonstrate the depth of knowledge behind your proposal, which is what gives finance leads confidence in recommending your solution.
The problem is that most mainstream solar proposal tools can't support that kind of scrutiny on the battery side. Tools like PV*SOL and Pylon were built for solar-first modelling. They're good for layout, yield and basic financials, but much less reliable for solar + battery projects.
For a battery case to stand up, your software needs three things most solar-first tools don't have:
- The client's half-hourly consumption data, not just an annual total
- Confidence that the battery and inverter are compatible with the control software
- A credible view of how the battery will actually be charged and discharged day to day
Expect to be asked about commercial battery storage if the site has expensive peak periods and a meaningful gap between cheap and expensive times of day.
Other questions likely to come up include:
- Whether solar would otherwise be exported at a low rate
- Whether an existing or planned EV charging setup will create demand spikes
- How the battery will perform if tariffs or site usage change after installation
Given the rising demand for solar plus batteries, the rest of this article focuses on what your commercial solar proposal software needs to do to let you qualify, present and defend a solar-plus-battery case.
Qualifying, presenting and defending a commercial proposition
Every commercial deal has three stages where you either keep control or lose it.
1. Qualify fast
Before spending a day or more on a proposal, you need six things:
- The client's actual electricity bills broken down by time of day, not just an annual total
- Confidence that the roof can take the weight
- Assurance the grid connection can handle the extra generation
- A realistic view of the value of surplus power going back to the grid
- Whether there's enough spread between cheap and expensive periods to make a battery worthwhile
- The battery, inverter and control software are all compatible
If any of this is missing, the model will be weak and it'll show under scrutiny.
Watch out for regulatory requirements that could block or delay the project. For example, if the local grid can't handle the full export from your solar installation, the DNO may require a G100 export limitation scheme, which caps how much power the site can send back to the grid. That changes the solar and battery business case, so highlight it early before you model the savings, not after.
SEAI's Solar PV for Business guidance backs this up. Front-load the site, finance, grid and operating questions before you commit time to modelling.
Good software helps you spot these dead ends early, so you only invest pre-sales time in jobs worth winning.
2. Order your presentation
Once the technical checks are done, present the commercial case in this order. Each step builds on the one before it, so the finance lead sees the strongest, most reliable number first.
- Start with the base case. This is the savings from solar generation and reduced grid imports alone, using the client's actual tariff and real usage patterns. This is the number you're happy to stand behind even as every other number gets questioned, because it's built entirely on real bills, real tariffs and real usage patterns.
- Add the battery value. Explain how it avoids peak charges, stores solar for later use and shifts usage to cheaper periods. Stick to what the system will actually do day to day.
- Split the reliable from the upside. The finance lead will focus on the battery numbers more than anything else, so make the split obvious.
- Separate trading and export. These are the least reliable numbers and can change quickly with rates and market conditions.
In GB, a rule change known as P415 has made it easier since November 2024 for commercial battery owners to access wholesale and balancing market revenue without switching suppliers. That can strengthen a proposal, but it should always be shown as upside, not blended into the base case.
If the finance lead can't see where the trading income ends and the guaranteed savings start, the proposal is more likely to fail. They can't tell which numbers are reliable and which are speculative, so they stop trusting any of them.
If your proposal software can't separate these layers cleanly, neither will your finance lead. Lead with one big number and they'll spend the rest of the meeting pulling it apart. Build up step by step and you take the decision-makers forward with you.
3. Hold under pressure
This is where the meeting steps up a gear. Welcome scenario questions like "What if you add EV chargers?" and "What if electricity prices move?" If you've built up from a solid base and your software lets you change the inputs live, those questions move the deal forward and strengthen your case.
If the finance lead can change the electricity price, restructure the peak charges, or reduce the site's expected usage and see how the numbers move in real time, the deal stays alive. This matters because battery value depends on when electricity is expensive, not just how much it costs on average, so a small change in tariff timing can shift the numbers significantly.
That's the difference between software that helps you produce a proposal and software that helps you win with one.
Using GridVolt's commercial energy proposal software
GridVolt's AI-powered software controls batteries, solar panels and EV chargers on site, deciding when to charge, discharge and shift usage based on live tariff and demand data. The result is real energy savings, with every asset on the client's site working as hard as it can to bring the bill down.
GridVolt's simulator runs on the same software. That means when you model a project for the finance lead, you're showing them what the live system will actually do on their site, not what a separate sales tool thinks it might do. The numbers in the proposal and the numbers on site come from the same place.
Installers already pay for proposal tools, and specialist battery modelling platforms cost more again. We give the GridVolt simulator away for free.
Installers use GridVolt across their customer sites, including existing ones where they swap out the previous control software. They also use the simulator in live client meetings to show the savings calculations in real time, so the finance lead can test the numbers before signing off.
Thomas Hayes, GridVolt's founder, works directly with installers to strengthen live commercial proposals. If you've got a deal where the battery case, tariff logic or control story needs to be stronger, that's where he comes in.
Contact GridVolt for a free compatibility check or to try the simulator on a live project.
Note: Image courtesy of Kaboom Pics.