Home Solar Batteries: 2. Modelling Performance

Home Solar Batteries - Modelling Performance

Introduction

This is the second in a series of entries looking to establish a reasonable view as to how the combination of solar PV and battery storage system should be modelled to ensure that information available to consumers should be considered accurate enough to establish a reasonable justification for investment in storage technologies.

If this is the first time you've accessed this information it is recommended that all of the relevant posts are considered in order through accessing the 'relevant posts' links

Investigation

In order to gain an understanding of the relative complexities involved in modelling the combination of solar PV and home battery storage solutions we really need to address the basics first, that is how can both the energy supply to charge the battery storage as well as the supply from the battery storage solution be modelled.

Image: Tesla

To achieve this we'll split the process into two streams and investigate the supply & demand elements independently, looking at alternative options and their relative advantages & disadvantages. At first glance it may look a little long-winded, but after much forethought it seems to be the appropriate route to take.

1 - Energy Supply to Charge Batteries

Solar Energy available to charge home batteries

In this section we will look at the various methodologies available to model the renewable energy available to charge the batteries and many of the relative flaws which each may have which can result in inaccurate or erroneous predictions of energy diversion to storage.

Domestic battery systems can be used by homeowners to utilise storage to shift demand to take advantage of charging systems using low cost energy supplied directly from the grid at 'off-peak' unit prices and using that energy to displace standard daytime or punitive peak rate unit purchases, which is a potentially useful prospect over the winter months.

At this particular stage it is not intended to look into utilising energy supply directly from the grid so that we can concentrate on renewable energy generation (PV) storage, however, the complexities of the mixed source scenario will be addressed later.

2 - Energy Demand Satisfied by Batteries

As well as looking at capturing energy into storage it is equally appropriate to address how the batteries will likely satisfy household energy demand. To achieve this we will address a range of energy usage data timescales upon which a model can be built and look at the effect of matching demand to supply.