This guide walks through how to model solar and battery systems in Kinesis, that can be used to predict outcomes such as how it affects electricity load profiles, or greenhouse gas emissions that could be avoided. If you are new to Kinesis, we suggest checking our Getting started guide.
Apps needed
Sustainability app (Kinesis)
Relevant attributes
Solar
The Solar attribute describes the different components of a solar PV system such as solar arrays and batteries.
Peak capacity (kW)
Peak capacity or the rated capacity is the maximum power output the panel could produce under ideal operating conditions. For solar PV sizing, peak capacity is often used as the unit for installation.
Storage (kWh)
Storage refers to the (effective) amount of energy the battery system can store.
Note: The usable or effective capacity is what's needed as input, and NOT the nominal capacity of the battery, which includes portion of the battery reserved for internal use.
Peak power (kW)
A battery storage unit takes time to charge and discharge. Peak power is how fast the battery can be discharged.
Rate of charge (kW)
The rate of charge is how fast the battery can be charged.
For example, a house with an installation of a 5 kW solar system and a Tesla Powerwall* would have the Solar attribute values of
| Peak capacity | 5 kW |
| Storage | 13.5 kWh |
| Peak power | 5 kW |
| Rate of charge | 5 kW |
*A Tesla Powerwall has the following performance specifications:
Solar PV sizing
Key factors that affect the optimal size of your solar system are physical space and energy requirement.
Physical space
One solar panel requires approximately 1.3 m2 of roof area, and an average 5kW solar system will have 20 panels in the solar array. The available roof area in your development limits the size of the solar system you can install.
Energy requirement
Generally, we want the solar energy production to closely match the energy requirements of a development. The Sustainability app provides a chart showing the monthly electricity demand of the project, and how that demand is met. The example below shows the monthly electricity demand of a 2-bedroom terrace in Sydney, without any solar systems in place, electricity is imported from the grid.
By adding a 1kW solar system, you can see below that a small portion is now coming from solar energy.
If we increase the size to 3kW to try and increase the solar consumption share, we see that it has increased slightly, but now the solar system is generating way more energy than what is required, but a lot of it is not getting used and is being exported to the grid.
We can add a battery to utilise the excess energy generated. The optimal battery sizing will largely depend on the energy design of the development, e.g. the optimal battery size for peak reduction, solar utilisation and net carbon zero would be different to to each other. But in general, an optimal battery should utilise the excess generation from the solar panels, meaning that the battery storage capacity is large enough to store the excess generation to avoid electricity export. The example below adds a 13.5kWh battery. You can see that the house is now mostly powered by solar energy.
It might take a few iterations to get the optimal size for your development. Once you have a few options, compare the outcomes of each to see if the desired goal (solar utilization / net zero emissions etc.) has been achieved.