Several sites in one project
Place sites on a map by clicking, entering coordinates or searching an address. Each site carries its own load, power system, solar, battery and design rules, which suits a rollout across a network.
Electrical System Design
BESS & Solar System Designer
Design off-grid, hybrid and grid-tied solar and battery power systems for communications sites, from the load and the local climate through to cable sizing and a design check.
Included in the 14-day Pro trial on every new account. No credit card.
Walkthrough
See it working
Step 12
Run the design check and save
The design check lists every error, warning and note for the site. Projects are saved to your account and can be exported as a file.
Saved designs listed alongside the option to start a new project.
Overview
What the BESS & Solar System Designer does
A standalone or hybrid power system for a remote radio, telemetry or repeater site is a chain of linked decisions. The load sets the size of the battery and the solar array, the local climate sets how much energy the array can collect through the year, and the power conversion equipment, cabling and protection all have to suit the result. When each step lives in a separate spreadsheet, the hand off between them is where errors creep in.
Read the full overview
The BESS and Solar System Designer keeps that chain in one place. You place each site on a map and the tool retrieves monthly irradiance and temperature for the location from NASA POWER. You then build the load from a catalogue of datasheet equipment or your own entries, choose how the site is powered (an inverter, a modular DC power system or an AC distribution board), and add solar, batteries and a backup generator where the chosen system can connect them.
Every change flows through to the analysis: solar yield on the tilted array, battery autonomy and ageing, an hour by hour dispatch across a year, generator run hours and fuel, cable voltage drop, and a design check that lists errors, warnings and notes for the site. Where a datasheet does not state a value, the tool flags the gap instead of quietly assuming a figure. Projects can hold several sites and are saved to your account.
Capabilities 8
Climate data from NASA POWER
Monthly irradiance and temperature for each site come from the NASA POWER climatology service. If the service cannot be reached, the tool uses a stored copy or a bundled dataset and labels the source, so you know what the design rests on.
Load from datasheet equipment
Build the site load from a catalogue of radio, network, fixed wireless, CCTV, server and cooling equipment, or enter your own items one at a time or by CSV import. Duty cycle and power factor are applied to give peak power, average power and daily energy.
Inverter, DC power system or AC board
Each site is built around an inverter, a modular DC power system or an AC distribution board. Parallel inverters are checked for whether the site still carries its peak load with one unit out, rectifier plant is sized for N+1 redundancy, and the AC board records assembly ratings, the prospective fault level and an outgoing ways schedule.
Solar array and string checks
Choose panels from the catalogue and split the array into sub-arrays with their own tilt, azimuth and string length. Yield uses Hay-Davies transposition onto the tilted plane, and each string is checked against the inverter tracker it lands on, including open circuit voltage on a cold morning and input current at 1.25 times short circuit current.
Battery sizing and ageing
The bank is sized for an autonomy target, depth of discharge and capacity buffer, with charge and discharge rates checked against the datasheet. Service life combines calendar ageing, scaled for the site temperature by an Arrhenius rule, with cycle ageing from the datasheet cycle life at the design depth of discharge.
Annual dispatch and generator forecast
An hour by hour dispatch across a year tracks state of charge, unmet load and generator running. It drives the loss of load probability against battery size, the depth of discharge and cycle analysis, and a forecast of generator run hours, fuel use and tank autonomy.
Cable sizing and a design check
Cable runs are sized for current and voltage drop to AS/NZS 3008.1.1, with resistance taken at the conductor operating temperature, and the total drop from source to load is checked against the AS/NZS 3000 limit. A design check gathers every failing and marginal result for the site into one list.
Inputs and outputs
What goes in, what comes out
Inputs 9
- Site locations by map click, coordinates or address search
- System type: off-grid, grid-tied or hybrid
- Equipment loads from the catalogue or entered by hand, with quantity, duty cycle and power factor
- Power system: inverter, modular DC power system or AC distribution board
- Solar panel, array size, sub-arrays, tilt, azimuth and string length
- Battery model, bank size and design depth of discharge
- Backup generator and its dispatch policy
- Cable runs with length and voltage
- Design rules such as autonomy, reliability and depth of discharge targets
Outputs 13
- Load profile with peak power, average power and daily energy
- Monthly and annual solar yield with tilt and azimuth sensitivity
- Battery capacity, autonomy, charge time and charge rate checks
- Battery capacity retention from calendar and cycle ageing
- Annual hourly dispatch with state of charge, depth of discharge and cycle analysis
- Loss of load probability against battery size
- Generator run hours, fuel use, fuel cost and tank autonomy
- Inverter utilisation and redundancy, and rectifier plant sizing
- Cable schedule with voltage drop and total drop from source to load
- Battery DC fault current estimate and required breaking capacity
- Cooling load, system efficiency and losses
- Design check listing errors, warnings and notes
- CSV exports and a JSON design file
Standards & methodology
- AS/NZS 3000 wiring rules for the voltage drop limit and distribution board checks
- AS/NZS 3008.1.1:2017 for cable current ratings and voltage drop
- AS/NZS 5033 for the PV string current check at 1.25 times short circuit current
- AS/NZS 61439.1 and 61439.2 for switchboard assembly ratings
- NASA POWER monthly climatology for irradiance and temperature
- Hay-Davies transposition for irradiance on the tilted array
- Arrhenius temperature scaling for battery calendar ageing
Use cases
When to use this tool
- 01Designing an off-grid solar and battery system for a remote radio, telemetry or repeater site
- 02Sizing a hybrid solar, battery and diesel system for a communications shelter
- 03Choosing rectifier plant and battery capacity for a DC powered telecoms site
- 04Checking how a battery bank will age under the site climate and load
- 05Forecasting generator run hours and fuel use for a hybrid site
- 06Sizing cable runs and checking voltage drop from source to load
- 07Preparing an AC distribution board schedule for a switchboard manufacturer to quote
- 08Planning power for several sites in one project
Where does the solar and temperature data come from?
Monthly irradiance and temperature for each site come from the NASA POWER long-term climatology. If the service cannot be reached, the tool uses a previously stored result or a bundled climatology dataset, and labels which source the design is using. Stored or fallback data is still valid input, but it is worth knowing before you rely on a result.
Is the annual simulation based on a typical meteorological year?
No. The dispatch runs hour by hour across a full year, but each month is built from a representative day shaped by that month's NASA POWER averages. It captures the seasonal balance between solar, load and battery well, but it will not show a run of unusually cloudy days within a month.
How is battery life estimated?
Capacity at a chosen design year is the lower of two estimates. Calendar ageing follows the warranty retention, sped up or slowed by an Arrhenius rule for the cell temperature, which is the site mean temperature plus an enclosure allowance. Cycle ageing uses the cycle life the datasheet gives at the design depth of discharge, and is not applied when the datasheet gives no cycle life.
Which Australian standards does it apply?
Cable runs are sized for current and voltage drop to AS/NZS 3008.1.1, and the total drop from source to load is checked against AS/NZS 3000. PV strings are checked at 1.25 times short circuit current per AS/NZS 5033, and the AC distribution board follows AS/NZS 61439 and AS/NZS 3000. The results support your design review; they do not replace it.
Does it check AS/NZS 4509, AS/NZS 4777 or AS/NZS 5139?
No. The tool shows which of these and other standards apply to each site, based on the system type and whether a battery is fitted, and counts each applicable one as not assessed. Compliance with them needs to be confirmed separately.
Can one project hold more than one site?
Yes. A project can hold several sites, each placed on the map with its own load, power system, solar, battery and design rules. This suits a rollout where sites share a design approach but differ in load or climate.
How do I save and share a design?
Projects are saved to your account and can also be exported and imported as a JSON file. The site list and equipment list download as CSV, and the AC distribution board schedule copies as CSV for a manufacturer to quote from.
Related
Related tools
Free for 14 days
Included in the 14-day Pro trial on every new account. No credit card.