Heat Pump vs Electric Hot Water System when you already have Solar Photovoltaic (PV) panels.
When you already have solar photovoltaic (PV) solar panels installed on your home and when roof space is limited, how do you choose between a heat pump hot water system and an electric water heater storage system for your hot water needs? It is essential that you consider how each option will complement your solar power system. In addition several factors need to be considered including your specific needs, budget and environmental considerations.
Here are some factors to consider when making your decision:
Efficiency: Heat pumps are generally more energy-efficient than traditional electric resistance heating. They can provide up to 3-4 times more heating energy than the electricity they consume. Electric resistance heating systems are far less efficient.
Use of PV Energy: Heat pumps can be configured to run during the day when your PV panels are generating electricity. In fact, many heat pumps now come with a built-in timer which can allow you to utilise your solar-generated electricity effectively. This reduces your reliance on the grid and potentially lowering your energy bills. You can still use your PV-generated electricity to power electric resistance heaters, but the efficiency may be lower, meaning you’ll need more PV capacity to meet your heating needs.
Budget: If upfront costs are a concern, electric resistive water heater systems are usually less expensive than heat pumps and will be a more affordable option. However, consider the long-term operating costs, as electric resistance systems will be less efficient and will result in higher energy bills. This may offset the initial cost savings. Heat pumps will be far more economical over time due to their energy efficiency.
Environmental Impact: Heat pumps have a lower carbon footprint than electric resistance hot water heaters because they transfer heat rather than generate it directly. Electric resistance heaters are less environmentally friendly leading to higher greenhouse gas emissions.
Rebates: The Federal Government offers an STC (Small-Scale Technology Certificates) rebate for heat pumps. In September 2023 and in addition to the STC rebate, the Climate Smart Energy Rebate was introduced. This rebate offers $800-$1000 for the installation of a heat pump hot water system and is applied for post installation. Whilst this funding is limited, it is certainly the right time to install an energy-efficient system. There are no rebates offered for electric resistance heaters.
If you have PV solar panels and want to make the most of your PV-generated electricity while reducing your environmental impact, a heat pump is the more favourable choice. However, consider your specific circumstances and financial constraints to make the best decision for your home.