How Apex works

Apex is a consumption-driven solar, battery and electricity-plan optimiser. From a power bill (or just a postcode) it models hundreds of solar and battery combinations against real electricity tariffs, then ranks the ones that actually pay off - by payback, return (IRR), 10-year value (NPV) or biggest saving.

It is built to answer "what should this customer install, and what plan should they be on" in seconds, and to turn that answer into a branded comparison report or a Solar Proof project.

Ideally a recent electricity bill (PDF or photo) - Apex reads the usage, rates and address straight off it. No bill? Just enter a postcode and an estimate of daily usage and Apex will look up the local tariffs and use a representative load profile.

Interval data (a NEM12 / smart-meter CSV) is optional but makes the result more accurate, because it models the customer's actual half-hourly usage instead of a typical shape.

Under a minute. Reading the bill takes a few seconds, and the optimiser evaluates the full grid of system sizes and every matching retail plan in one pass.

The "Magic Bill" step uses AI to extract the usage, tariff rates, supply charge, feed-in tariff, billing period, retailer and site address from the uploaded bill. It fills the wizard for you.

Always glance over the extracted rates before trusting the result. AI extraction is very good but not perfect - a mis-read tariff is the one thing that can throw the plan comparison off. The rates are editable in step 1.

Apex flags a bill more than about two years old. Electricity tariffs move, so an old bill's "stay on your current plan" baseline is unreliable and can make an outdated plan look artificially cheap. The system sizing and savings are still a sound guide - but enter today's rates for an accurate plan comparison.

Apex matches your total usage to a real, classified load profile (home, work-from-home, business, and so on), scaled to the entered consumption. If the site is linked to a Solar Proof project with metered data, it uses that instead. The data basis is always shown under the results.

It does not ask you to pick a size. It simulates a full grid of solar and battery sizes (per segment - residential vs commercial), dispatches a battery hour by hour against the tariff, and scores every combination. You see the whole field ranked, with the best highlighted - not just one suggested size.

• Year-1 bill - the electricity bill with that system, on its best plan.
• Bill saving - reduction vs the current bill.
• Total saving/yr - bill saving plus VPP/FCAS plus incentives (see below).
• Payback - years for the saving to repay the system cost.
• 10-yr NPV - lifetime value in today's dollars (discounted).
• IRR - the effective annual return over a 25-year life.
• Self-use - share of solar used on site rather than exported.

Total saving is the whole benefit stack: bill saving + VPP/FCAS + incentives (LGCs). Hover the total for its breakdown, or open the "Value breakdown" chart to see each stream per option. If the total looks higher than bill saving alone, the difference is the market/incentive streams.

Yes. By default Apex sizes with generic assumptions, but the moment you pick a real panel it uses that panel's warranted output-degradation curve and temperature coefficient, and a real battery brings its own cycle life, warranty and usable capacity. So a premium panel that degrades slowly, or a battery with a longer cycle life, will show a genuinely better lifetime value (NPV/IRR) than a budget equivalent of the same size - because it lasts longer and needs replacing later, if at all.

This is what makes Apex a real feasibility tool rather than a rule-of-thumb: the gear you actually sell drives the return.

Open an option's detail (click its row), then "Choose real products" and search your catalogue for the panel, inverter and battery. Apex re-sizes to whole panels / battery modules that hit the option's kW and kWh, and re-costs that option live. There is also a one-tap shortcut from your saved kit.

Tick "Apply picks to all options" in the products panel and the product you choose is set across every option and the whole grid is re-costed against it. That gives you a consistent baseline - say, your standard panel and battery - so every size is compared on equal, real-world footing.

From that baseline you then pin specific options with alternative gear to compare the upgrade side by side (see below). It's the fast way to build a "good / better / best" comparison: set the baseline once, then swap gear only where you want to show the difference.

Pinning locks an option (a fixed system size) into the comparison so you can put two products head to head at the same size - for example the same 6.6 kW with a budget panel vs a premium panel, or two different batteries. Each pinned variant carries its own price and re-costs its own payback and NPV, and they appear side by side in the comparison report.

So the workflow is: set a baseline product across all options, then pin the handful of options where you want to show an upgrade, each with the alternative gear.

Yes. Each option has an editable price so you can match your real quote instead of Apex's estimate - the payback, NPV and IRR recompute from your price. Pinned variants each keep their own price too.

From the public Consumer Data Right / AER retail plan feed, refreshed regularly. Apex simulates the customer's usage on each matching plan (including weekday/weekend and seasonal time-of-use rates) and shows the cheapest, plus the runner-up and third place.

Apex resolves the local network (DNSP) from the postcode and models its peak-demand charge, which matters for commercial sites - a battery that shaves the peak reduces it. Some DNSP rates are marked "indicative" where the exact schedule isn't confirmed; confirm from the bill for a firm C&I quote.

A battery can earn money providing grid services - either a guaranteed retailer VPP credit ($/kW-yr) or the FCAS market, valued on the battery's power rating and its dispatch-derived availability (a hard-working battery has less spare power to sell). It is shown as its own stream so you can see it separately from bill savings.

On a wholesale (spot) plan the customer pays - and is paid for exports - the live market price rather than a flat rate. A battery can charge when the price is cheap and sell into the evening price spikes. Apex adds this plan automatically where market data is available for the region, and only wins when it genuinely beats the flat and time-of-use plans for that load.

They answer different questions:

• Peak spot (max seen) is the single highest price ever recorded in that hour - a rare extreme. In a scarcity event the market price can hit its cap (around $16.60/kWh) for a few minutes, maybe a handful of times a year.
• Battery capture price is what a battery realistically and repeatably earns discharging into the evening high-price window - modelled as the average price plus 1.5 standard deviations, capped at the observed max.

A battery cannot reliably hit the exact top tick every day (that needs perfect foresight and the spike to land while it still has charge), so crediting the absolute peak would badly overstate returns. Apex deliberately credits a realistic, repeatable uplift instead - which keeps the wholesale case credible.

On the chart, the shaded band is a typical evening spike (roughly the 90th-percentile price), the amber bars show the battery selling into it, and the red "Max seen" marker calls out the once-a-year extreme without letting it distort the scale.

It is modelled from the statistical spread of historical spot prices (average, volatility and observed maximum per hour and season), not a replayed real-time feed, and it is deliberately conservative. Treat it as a well-grounded estimate. For a firm Amber pitch, sanity-check against a real Amber bill.

The battery's purchase price is counted once, upfront, in the system cost. Apex does not also subtract an annual "wear" charge - doing both would double-count the battery.

Instead, it works out when the battery reaches end of life - the shorter of its calendar warranty and its cycle warranty at the modelled cycles per year - and books a real replacement cost in the NPV/IRR only if that falls within the analysis window, crediting any unused life left at the end. So a lightly-cycled battery that outlives the horizon carries no phantom cost, and one cycled hard enough to wear out early is charged a genuine replacement.

Yes. When you pick a specific battery, Apex uses its real cycle life, warranty and usable capacity. A premium cell with a higher cycle life or longer warranty lasts longer, needs fewer replacements over the life, and so shows a better return than a budget cell of the same size.

Payback is system cost divided by the annual benefit. NPV discounts the yearly benefit to today's dollars (10-year horizon), and IRR is the effective annual return solved over a 25-year life. Both bake in power-price escalation, the panel's real output-degradation curve, and the battery replacement/residual described above.

• Power-price escalation - savings rise each year with prices (adjustable in step 2).
• Panel degradation - the selected panel's warranted output curve, so premium and budget panels genuinely differ.
• Temperature - the panel's temperature coefficient adjusts output vs a standard panel.

The assumptions actually used are listed under each result.

Apex is a modelled estimate (beta), not a guarantee. It is built to be defensible and conservative, but it depends on the inputs - especially the tariff. Confirm rebates, tariffs and product availability before quoting, and for high-stakes commercial jobs sanity-check against the customer's actual bills.

Yes. Tick the options to compare and generate a branded comparison report (PDF), or create a shareable link that the customer can open in a browser - no login needed.

Yes - "Use this system" creates a Solar Proof draft project seeded with the chosen solar, battery, products and address, and opens it on the map with an on-screen target so you can design straight to the recommended size. This is the workflow loop that a standalone calculator can't offer.

Apex is in active beta. If a number looks off, check the tariff first (it drives everything), then the data basis note under the results. Feedback is very welcome while we harden it for launch.