Quote Solar + Storage Without Leaving the Design
Choose on-grid, hybrid or off-grid at project creation. Size the battery around the customer’s tariff or backup requirement, then carry it into the same simulation, bill of materials and proposal as the array.
Hybrid system
Size the battery
Capacity recommendation
13.5 kWh
Example project
Load covered
Critical loads
8
Backup target
12 hr
Reserve
20%
3
System types — on-grid, hybrid, off-grid
4
Storage modes, gated by system type and tariff
6
Metering arrangements modelled
18
Pages in the off-grid proposal specification
System Type Is a Design Decision, Not an Afterthought
Battery attach usually happens twice: once in the design tool, which does not model it, and again in a spreadsheet that does. The two disagree, and the proposal reflects whichever one the salesperson opened last.
In SurgePV the system type is chosen when the design is created, alongside the default profile. On-grid hides the battery page entirely. Hybrid and off-grid put battery sizing into the workflow between payment and proposal, where it belongs — one model, one set of numbers.
Which modes are available depends on the tariff as well as the system type. A time-of-use tariff unlocks all four. A flat tariff leaves the two backup modes, because arbitrage against a single rate has nothing to arbitrage. With no grid at all, critical-load backup is the only mode that means anything.
System types
On-grid
DefaultStudio → payment → proposal. No battery, and no battery page to distract from it.
Hybrid
Up to 4 modesStudio → payment → battery → proposal. Grid-connected with storage; every mode is on the table.
Off-grid
2 modesBattery required, backup modes only, and a dedicated proposal built for a system with nothing to export to.
A Battery Does One of Four Jobs. Pick the One You Are Selling.
Each mode changes how the battery is sized, how it is scheduled through the day, and what the customer sees at the end. Sizing a backup battery on arbitrage logic is how quotes end up wrong.
Self-consumption bill savings
Hold solar that would otherwise export and spend it against your own consumption. Charge from solar, discharge to load, and split the day into peak and off-peak periods from the tariff itself.
Requires: Time-of-use tariff
Offset peak ToU rates
The same machinery aimed at price rather than volume — the battery is sized and scheduled around the highest-rate period of the day instead of the highest-consumption one.
Requires: Time-of-use tariff
Backup critical appliances
Size from the appliance list rather than the tariff. Reports how long the battery alone carries the critical load, how long it carries the full load, and how far solar plus storage stretches the critical load.
Requires: Any tariff, including no grid
Full home backup
Give a target duration in days and hours, or a percentage of consumption to cover. Half of average daily usage is the starting point if you have no figure in mind.
Requires: Any tariff
Peak shaving
On the two tariff-driven modes, cap the battery's charge rate at the consumption peak so that charging the battery does not itself create the demand charge you installed it to avoid.
Reserve for backup
Hold back a percentage the battery will not discharge past, and see how many hours of backup that reserve actually buys — arbitrage and resilience from the same asset, quantified separately.
Where a profile lives
Organisation
Named profiles your team maintains once — appliance, quantity, wattage, the hours it runs, and whether it is on backup. Only appliances marked for backup carry into a project.
Project
The chosen profile, editable for this customer. Swapping profiles after a battery exists asks first, because it invalidates the sizing that battery came from.
Battery page
Read-only. Changes route back to the energy page, so the number on the design always traces to a profile someone deliberately edited.
Backup Is Sized From When Appliances Run, Not Just How Much They Draw
The quick way to size a backup battery is to total the critical loads and spread them across a generic load shape. It is also wrong: a fridge cycling all night and a well pump running for twenty minutes at dawn have very different consequences for a battery, and the average hides both.
Because every appliance in a critical-load profile carries its own running hours, SurgePV builds a purpose-made hourly profile that places each appliance's energy at the hours it actually runs. Backup duration then falls out of walking the battery down that curve hour by hour, counting the hours before it runs flat.
Add solar and the same walk runs against residual load — generation serves the appliances first and only the shortfall touches the battery. Charge and discharge rates are capped by the inverter and the battery's own C-rate, so the answer respects the hardware rather than assuming an ideal one.
The Meter Decides What a Battery Is Worth
The same battery on the same roof is a good investment under one metering arrangement and a poor one under another. SurgePV models six, and hides the modes that a given arrangement makes meaningless rather than quoting savings that will not materialise.
NM-RF
Net metering, retail rate with fixed price
NM
Net metering
NB
Net feed-in tariff (net billing)
GM
Gross metering
ZE
Net metering with zero export
EO
Net metering with export only
Modes that do not apply are not offered
Under gross metering and export-only arrangements, the two self-consumption modes disappear — the meter does not let solar offset consumption, so there is nothing for the battery to shift. Under standard net metering, self-consumption is flagged as close to break-even before you build a quote around it.
Backup modes are available on every arrangement, but they are modelled for runtime, not bill savings. A backup battery is resilience, and SurgePV does not dress it up as arbitrage.
Three savings figures, kept separate
Solar savings
The bill with solar against the bill without it.
Storage savings
What the battery adds on top of solar. Shown on the internal battery decision card, deliberately not on the customer proposal.
Total savings
Computed directly from the post-solar simulation. This is the proposal headline and what the cashflow is built on.
They are three independent results, not two parts and a sum. Fixed charges, minimum bills and export credits interact, so treating them as additive would overstate the case.
An Off-Grid Proposal That Answers Off-Grid Questions
A grid-tied proposal leads with offset and payback. Neither means anything to a customer with no grid connection, and grid-independence charts on an off-grid system are worse than useless — so they are removed rather than left showing an empty result.
What replaces them is what an off-grid buyer actually asks: how big is the battery, and how many days will it carry me. Battery capacity joins the at-a-glance summary on the cover, and the system overview leads with battery size and days of backup.
The battery page carries
Appliance load breakdown — quantity, power, average daily hours, daily energy
Average daily energy demand
Peak load demand
Night-time energy requirement
Battery size
Days of backup — storage with critical load, storage with full load, and solar plus storage with critical load
Evidence-first evaluation
Evaluate SurgePV with your own project
SurgePV does not publish customer names, quotations, or performance outcomes without retained consent and substantiation. Use a representative project during a guided demonstration and validate workflow, outputs, assumptions, and fit against your own requirements.
What is solar battery design software?
It sizes and schedules a battery alongside the PV array rather than after it — modelling how the battery charges, when it discharges, and what that is worth under the customer's tariff. In SurgePV it sits inside the same design as the array layout and the financial model.
Can I design off-grid systems?
Yes. Off-grid is one of three system types chosen when the design is created. It requires a battery, offers the two backup modes, and produces a proposal built around battery size and days of autonomy instead of grid offset.
How is battery size calculated?
It depends on the mode. Tariff-driven modes size against consumption or price across the chosen period. Backup modes size from the critical-appliance list, using an hourly profile built from each appliance's own running hours rather than a generic load shape.
Frequently Asked Questions
Does SurgePV design hybrid and off-grid systems?
Yes. System type — on-grid, hybrid or off-grid — is chosen when the design is created. On-grid designs hide the battery page. Hybrid and off-grid designs require a battery and add battery sizing to the workflow before the proposal is generated.
Which storage modes are supported?
Four: self-consumption bill savings, offset peak time-of-use rates, backup for critical appliances, and full home backup. The first two require a time-of-use tariff. The two backup modes work on any tariff, including systems with no grid connection.
How does SurgePV size a backup battery?
From the critical-load profile. Because each appliance carries its own quantity, wattage and running hours, an hourly load profile is built that places energy at the hours it is actually used, then the battery is walked down that curve to find how many hours it sustains. With solar in the design, the same walk runs against residual load after generation.
Do critical-load profiles carry across projects?
Yes. Profiles are defined at organisation level and reused across projects, so a team standardises once. Only appliances marked for backup propagate into a project, where they can still be adjusted for that customer.
Which metering arrangements are modelled?
Six: net metering with retail rate and fixed price, standard net metering, net feed-in tariff or net billing, gross metering, net metering with zero export, and net metering with export only. Fixed charges and monthly minimum bills are applied in the order the tariff applies them.
Does the battery appear in the proposal and the BOM?
Storage results carry into the same simulation, bill of materials and proposal as the array. Off-grid designs get a dedicated proposal whose battery page shows the appliance breakdown, key load metrics and days of backup.
Quote Storage in the Same Design as the Array
Bring a project with a battery attached and we will model it end to end — mode, metering, savings and proposal.
