BrightGridOne of the simplest ways to evaluate solar panels is to compare two futures: continuing to purchase electricity from the grid or installing solar and generating some of your own electricity. The right answer depends on the installation cost, your electricity consumption, solar generation, export payments and how long you expect to remain in the property.
Solar versus no solar
Without solar, your household remains dependent on electricity purchased from your supplier. With solar, some of your annual electricity demand can be supplied by your own generation. Surplus electricity can potentially be stored in a battery or exported to the grid.
| Factor | No solar | Solar |
|---|---|---|
| Upfront cost | Usually none | Installation investment required |
| Grid electricity | All household electricity is purchased | Solar can reduce imported electricity |
| Export income | None from solar | Possible for eligible exported generation |
| Energy generation | None on site | Electricity generated on the property |
| Long-term exposure | Continued exposure to electricity prices | Part of demand can be supplied by generation |
Where do solar savings come from?
The primary saving comes from using solar electricity instead of purchasing electricity from the grid. The value of each kilowatt-hour depends on when the electricity is generated and when your home consumes it.
Self-consumption is important
A household that uses a large amount of electricity during daylight hours may naturally consume a greater proportion of its solar generation. Homes with low daytime demand may export more electricity unless a battery or flexible load is available.
Why a 20-year comparison is useful
Solar panels are long-term assets. Looking only at the first year can make it difficult to understand the lifetime value. A longer model can include electricity savings, export income, maintenance assumptions and equipment replacement considerations.
- Initial installation cost
- Annual solar generation
- Household electricity consumption
- Self-consumption percentage
- Export income
- Electricity price assumptions
- System degradation
- Inverter replacement assumptions
- Monitoring and maintenance costs
Do not use a generic savings figure
Two houses can have identical solar systems but very different financial outcomes because their electricity consumption and usage patterns are different.
When does solar tend to make the most sense?
- The roof has good solar exposure.
- The household uses a meaningful amount of electricity.
- The property is expected to be occupied for many years.
- A reasonable proportion of solar can be consumed on site.
- The installation is professionally designed and installed.
Compare solar with your current electricity costs
Model the long-term difference between continuing with grid electricity and installing solar for your home.
Check Your SavingsFrequently asked questions
Is solar cheaper than buying electricity from the grid?
Solar can reduce the amount of electricity a household needs to purchase from the grid. Whether the investment provides an attractive return depends on installation cost, generation, consumption and tariffs.
Is solar worth it over 20 years?
A long-term comparison can show the potential value of solar beyond the initial payback period. The result depends on the property and the assumptions used.
Does solar increase property value?
Solar may be attractive to prospective buyers because it can reduce electricity demand from the grid, although the impact on property value varies by property and market.
Should I buy solar if I plan to move?
It depends on the expected financial return, how long you plan to stay and how the system may affect the property's appeal to future buyers.
Marcus Webb
Head of Engineering at BrightGrid Energy
