The Microgeneration Certification Scheme (MCS) is the UK’s quality standard for small-scale renewable energy installations, and MCS-certified installers must give customers a standardized performance estimate, with specific disclaimers, before a contract is signed. Aurora calculates production and self-consumption the MCS way and adds the MCS table and disclaimer to your proposals, so your figures follow the MCS method without manual calculations. MCS is available to all UK accounts.
In this article:
- How MCS works in Aurora
- Set MCS as your account default
- Add the MCS table and disclaimer
- Select the occupancy archetype
- Switch a design to MCS
- When Aurora can’t use MCS
- FAQ
- Related articles
How MCS works in Aurora
When a design uses the MCS simulation engine, Aurora calculates its figures the way MCS prescribes:
- Estimated annual output is installed capacity (kWp) × the MCS kWh/kWp value (Kk) for the site’s postcode region, orientation, and inclination × the shade factor (SF).
- Shade factor comes from Aurora’s shading analysis instead of the MCS shading method — MCS allows alternative methods that are equivalent or better. Aurora calculates each panel’s solar access and averages it across the array and over the year.
- Self-consumption is interpolated from the official MCS self-consumption tables, based on the household’s occupancy archetype, annual electricity consumption, and battery storage.
Design Mode, Sales Mode, and your proposals all show these MCS figures, so they match the MCS table. The MCS tables only cover typical homes — for example, annual consumption and estimated annual production must be under 6,000 kWh. For designs outside that range, see When Aurora can’t use MCS.
Set MCS as your account default
Only admins can change performance simulation settings. New designs, including designs created in Sales Mode, use the default.
- In the left navigation, click Settings.
- Under Projects and designs, click Performance simulations.
- Click Edit.
- Under General, open the Simulation dropdown and select MCS.
- Click Save.
The Simulation setting now shows MCS. For the other settings on this page, see Performance simulation settings – Account configuration.
Add the MCS table and disclaimer
Add the MCS table and MCS disclaimer blocks to a proposal template once, and Aurora fills them in for every proposal that uses it. To find and open your templates, see Sales Mode: Proposal Templates Configuration.
- Open the template in the proposal template editor.
- Click Blocks.
- Under Summary line items, drag MCS table onto the template.
- Drag MCS disclaimer onto the template.
- Click Save.
The MCS table has five sections:
- A. Solar PV installation — installed capacity, orientation, inclination, and postcode region
- B. Performance calculations — Kk, shade factor, and estimated annual output
- C. Estimated PV self-consumption – PV Only
- D. Estimated PV self-consumption – with EESS (an electrical energy storage system, such as a battery)
- E. Additional benefits from PV and EESS
The disclaimer explains that the estimate is guidance only, how Aurora calculates self-consumption and the shade factor, and that the figures aren’t a guarantee of performance.
Select the occupancy archetype
The occupancy archetype describes when the household is usually home on weekdays. MCS uses it to estimate self-consumption, so choose it based on a conversation with the homeowner. You can use any energy usage input method.
- Open the project and click Energy usage.
- Open the Usage pattern dropdown.
- Under Lifestyle based, select the pattern that matches the household.
| Usage pattern | Household |
|---|---|
| UK MCS: Home all day | At least one person is generally home between 9am and 5pm on weekdays |
| UK MCS: In half the day | The home is usually empty for half the day on weekdays — either all morning or all afternoon |
| UK MCS: Out during the day | The home is usually empty on weekdays |
If you don’t know when the household is home — for example, on a new build — select UK MCS: In half the day, as MCS specifies.
Switch a design to MCS
Anyone who works in Design Mode can change a design’s simulation engine — for example, to use MCS on a design created before your account default changed.
- Open the design in Design Mode.
- In the toolbar, click Settings (the gear icon).
- Click the Simulation tab.
- Open the Simulation engine dropdown and select MCS.
- Click Simulate system.
When the simulation finishes, the button reads Simulation updated. If Aurora can’t use MCS for the design, a warning appears instead — see When Aurora can’t use MCS.
When Aurora can’t use MCS
If a design is outside what the MCS method covers, Aurora automatically runs a full performance simulation with the Aurora or PVWatts engine instead — PVWatts if the panels aren’t connected to inverters. A Performance simulation warning lists the reasons and names the engine Aurora used.
Reasons include:
- Annual consumption is outside the MCS range
- Estimated annual production is outside the MCS range
- The battery’s usable capacity is outside the MCS range
- The design includes a heat pump
- The project’s usage pattern isn’t one of the UK MCS patterns
If the usage pattern is the reason, select a UK MCS pattern — see Select the occupancy archetype — then click Simulate system again. For the other reasons, check the design’s inputs. If they’re correct, the design is outside what MCS covers, so its figures come from the engine named in the warning.
FAQ
Can users change the simulation engine in Sales Mode?
No. Sales Mode doesn’t have a simulation engine setting. To change a design’s engine, open it in Design Mode.