Battery Storage Design Software for Solar Installers and EPCs

Battery storage design software should size battery energy (kWh) and power (kW). It should also model dispatch, which is when the battery charges and discharges, against your tariff (your electricity price plan). Then it should export a report that others can check. Aurora, OpenSolar, PV*SOL, PVsyst, SAM and Energy Toolbase each document storage modeling, with different operating modes and prices. Cell-level tools such as PyBaMM model battery chemistry, not PV-plus-storage projects (solar panels plus a battery).

SurgePV publishes this guide and sells one of the tools listed. That tool is solar design software. The table below shows what each vendor documents on its own site, read on 28 October 2026. It does not score accuracy.

What is the difference between storage software and cell design software?

“Energy storage software” and “BESS software” (battery energy storage system software) mean tools that model a battery inside a solar or grid project. They cover sizing, charge and discharge rules, tariffs and bill savings. Battery cell design software works one level down. It simulates the electrochemistry inside a cell, which is the chemical reactions that store energy. It uses models such as DFN (Doyle-Fuller-Newman), SPM (single particle model) and SPMe (single particle model with electrolyte). The open-source tool PyBaMM lists all three in its documentation. If your question is how a cell behaves, you need a cell-level tool. If it is how a battery changes a site’s bills, imports and exports, you need the project-level tools below.

How do the BESS design tools compare?

Sources: Aurora pricing and its storage simulation help article; OpenSolar battery model and its 16 February 2026 pricing post; PV*SOL product page; PVsyst shop; SAM battery storage and SAM home; Energy Toolbase ETB Developer and pricing pages.

For a wider list that includes design, shading and proposal features, see the top solar software tools for installers and EPCs.

What Each Tool Documents

Aurora Solar

Aurora’s help article says a design needs at least one connected battery before you run a storage simulation. In the battery inspector, you set the operating mode and the backup reserve (charge kept back for outages). These settings apply to every storage component in the design. If a design mixes battery types, the simulation adds up their capacity and output. Aurora calls the result an approximation. It suggests one battery type per design for more precise results.

OpenSolar

OpenSolar’s battery article says it tracks the battery’s state every hour of the simulation. It works out a single-trip efficiency as the square root of the round-trip efficiency. Round-trip efficiency is the share of energy you get back after charging and then discharging. OpenSolar applies the single-trip figure to both charging and discharging. It tracks kWh throughput (the total energy moved through the battery) to model degradation, which is the loss of capacity over time. The “Maximize Savings” scheme uses time-of-use prices. OpenSolar recommends the “Self-consumption” scheme if you are unsure of the battery’s control capabilities. A Load Offsettable setting handles cases such as a battery on one phase of a three-phase supply.

OpenSolar’s 16 February 2026 post says the core app stays free. It also says charges from 16 April 2026 apply to API Access (a way for other software to connect) and supported connectors.

PV*SOL

Valentin Software’s PV*SOL page lists battery-system simulation, project reports you can configure and export to Word or PDF, and circuit diagrams that can be prepared for submission to authorities. The listed 585 EUR plus VAT is for a one-year named-user licence (tied to one named person) without 3D visualization. It is one offer. Confirm the edition, renewal and support terms before you buy.

PVsyst

PVsyst’s documentation covers several storage modes for systems linked to the grid. In self-consumption with storage, energy is stored when PV output is higher than user needs. It is then used for internal needs until the battery is empty. The page says a charging and discharging strategy for time-dependent tariffs “is not yet implemented”. It also says battery energy is never reinjected into the grid in this mode. Other pages cover peak shaving, power shifting and weak-grid islanding. Peak shaving cuts the highest power peaks. Islanding means the site runs on its own, apart from the grid. Ask for the model files, version and parameters so a second reviewer can repeat the study.

SAM

The System Advisor Model from the National Laboratory of the Rockies models lead-acid, lithium-ion, vanadium redox flow and all-iron flow batteries. Its distributed financial models cover behind-the-meter storage, where the battery reduces a customer’s bill. The PPA (power purchase agreement) and Merchant Plant models cover front-of-meter storage. There the energy is sold. SAM has no standalone battery model. Its documentation says you can model one with the Generic Battery configuration and a plant loss of 100%.

What must BESS design software model?

Draw where PV, battery, converters, meters and loads connect. AC- and DC-coupled designs have different conversion paths. OpenSolar’s article gives one example. With a 5 kW inverter and 8 kW of PV, a DC-coupled battery can take the 3 kW the inverter cannot. An AC-coupled battery charges after the inverter. Also state where you measure (the meter boundary) and which losses each rating includes.

Check these for the planned equipment:

• Maker compatibility, plus the firmware (the device’s built-in software) or control links it supports.
• PV string voltage and current limits, battery voltage and current limits, and converter ratings.
• Continuous and peak charge and discharge power, with the state-of-charge (how full the battery is) and temperature conditions.
• Allowed export and import behaviour, and how it is measured and controlled.
• If backup is included: how backed-up loads are isolated from the grid, which loads are selected, starting requirements and recharge behaviour.

A catalogue entry in a tool does not prove that two products are approved to work together. The hybrid inverter guide and the backup battery design guide cover the equipment questions.

How do you size energy and power separately?

Start with load and PV data that line up in time. Test seasonal days and the charging and discharging window. For an outage study, list critical loads, concurrent power (loads running at the same time), startup demand and starting state of charge.

Here is a hypothetical example. You need 6 kWh AC energy. Assume an 80% nominal-energy operating window. That means you use 80% of the battery’s rated energy. Assume 95% one-way discharge delivery. That means 95% of the energy leaving the battery reaches the load. Then 6 ÷ (0.80 × 0.95) = 6 ÷ 0.76 = 7.89 kWh nominal DC energy. This is a sizing input. It is not a battery choice or a backup runtime. If a figure is already usable or delivered AC energy, applying the factors again counts the losses twice. Round-trip efficiency covers a full cycle. It is the wrong factor for a battery that is already charged.

Get cycle life, degradation, efficiency and usable capacity from the datasheet of the exact equipment. Use its operating conditions too. Do not take these figures from the chemistry name. Cycle life is how many charge cycles the battery lasts.

Test Dispatch Economics on One Small Case

Here is a hypothetical batch. You charge with 5 kWh AC energy at 90% AC-to-AC round-trip efficiency. It delivers 5 × 0.90 = 4.5 kWh AC. Assume all of it replaces imports (power bought from the grid) at £0.30/kWh, with no other limits or costs.

These are two ways to charge the same batch, so do not add them. They leave out battery wear, auxiliary losses (power the system itself uses) and tax. Do not multiply by 365 unless the chance to charge and the demand to discharge repeat every day.

A full model needs more inputs. These are tariff periods, reserve settings, degradation, replacements and financing. They also include demand-charge rules, which are fees based on your highest power use. Add export opportunity cost, which is what you give up by not exporting. Add whether grid charging is allowed. A standing charge you still pay is not a saving. Compare against a solar-only baseline. Then you do not credit the whole PV saving to storage.

Before you quote incentive values, check them against the current programme rules and the installation date. The solar NPV, IRR and payback guide covers the finance side.

How do you run an acceptance test before you buy?

Pick one test project with the same inputs for every vendor. Ask each vendor for this set of outputs:

1. Load and generation data with timestamps, units, sources and how missing data is handled.
2. Exact equipment, system layout, usable and nominal capacity, and conversion boundaries (where energy changes form).
3. Dispatch strategy, state-of-charge limits, backup reserve and power limits.
4. Energy-flow results by time interval (or similar detail), with an energy balance that adds up.
5. Solar-only, storage and sensitivity cases (what-if runs) on the same baseline inputs.
6. Financial assumptions, tariff dates, costs, replacements and financing.
7. Reports or model exports, revision history, and who owns each open engineering review.

Test a full battery, an empty battery, the charge-power limit, the discharge-power limit and an export limit. Look into any change in imports or savings that you cannot explain. Ask about integrations, data export, permissions, support and licence cost. Ask separately whether the tool controls a live system. A design tool is not an energy management system.

A permit, safety or interconnection (grid connection) flag in a tool is a prompt to review. It is not the rule itself. The requirements come from the project’s jurisdiction, which is the local legal area. They also come from the equipment and the responsible authorities.

What if you buy design services instead?

You can pay a provider to produce the design instead of buying software. If so, give the provider a clear brief. List the use case, power and duration, operating modes and critical loads. List the existing PV and service, site conditions, fire requirements, control interfaces and project stage. Also require named hand-off points between the electrical, structural, fire, controls, civil, utility and commissioning teams. The buyer’s guide to solar design services and the in-house vs outsourced comparison cover how to scope and test a provider.

Evaluate the Workflow in a Demo

Bring the acceptance test above to a SurgePV demo. Ask which inputs, storage models and exports are supported for your project. SurgePV’s published scope does not list battery dispatch. Ask what the workflow covers before you plan around it.

Frequently Asked Questions

What is BESS design software?

BESS design software sizes a battery energy storage system (energy in kWh, power in kW). It models how the battery charges and discharges against a load and tariff. It also exports results for a proposal or an engineering review. It differs from battery cell design software, which models the chemistry inside a cell.

Which battery design software is best?

No single tool fits every project. Match each tool’s documented operating modes and project scale to the outputs you need: load, dispatch, engineering, reporting and financial. Then run the same test project through each tool before you buy.

I need battery design software that supports DFN, SPM or SPMe workflows. What should I consider?

DFN (Doyle-Fuller-Newman), SPM (single particle model) and SPMe (single particle model with electrolyte) are cell-level electrochemical models. PyBaMM’s documentation lists all three. Solar-plus-storage design tools model the system around the battery, not the cell. Pick by your question: cell behaviour or project energy flows.

Can PVsyst model storage?

Yes. PVsyst’s documentation describes self-consumption, peak shaving, power shifting and weak-grid or islanding storage modes. In its self-consumption mode, a charging strategy for time-dependent tariffs is not implemented. Check the mode and version against your dispatch strategy.

Is DC-coupled storage always more efficient?

Topology (how the parts connect) alone does not settle it. Compare the conversion paths, operating conditions and measurement boundaries. Use the exact equipment data.

Is round-trip efficiency a backup discharge factor?

Not by itself. Round-trip efficiency covers both charging and discharging. A battery that is already charged needs different figures. Use the one-way delivery and available-energy figures at the stated boundary.

Can software certify a battery installation?

No. A design result or compliance flag cannot replace other checks. You still need maker compatibility checks, qualified engineering and installation review. You also need approval by the authority. Commissioning means final testing before use.

How should I compare battery software prices?

Compare the exact edition, licence period, users, tax, support and renewal terms. The published price for one offer is not the total cost of a storage workflow.