Collect and harness the free and renewable energy from the sun to provide electricity to run your home or business.
How solar works
Direct Current (DC), Alternating Current (AC).
- Solar Panels- The panels are made of photovoltaic (PV) cells, which convert sunlight into DC electricity throughout the day. Panels are usually connected in series to form solar arrays. Ideally, solar modules need to face true north at 25 -35 deg. pitch without any shading obstruction like trees or chimneys etc. but this can sometimes be compensated for by simply adding extra modules if roof space allows.
- Inverter- This device converts the DC electricity generated by the solar panels into the AC electricity that you need to run your home or business. A string system has one inverter and is generally used were all panels are facing in the same direction and have no shading issues. The size of the inverter relates to how many panels you have installed. A micro-inverter system has many smaller inverters for each/or a small group of solar panels and are used when the solar panels are installed on a multi directional roof and/or has shading issues.
- Switch Board- Connects your inverter to your home or business and to the power grid.
- Import/Export Meter – Your standard meter will need to be changed to an import/export meter. This meter measures the amount of electricity that is purchased from the grid (imported) and the amount of electricity sold to the grid (exported). Note: only some energy retailers accept exported power.
Solar power or solar hot water?
Solar power creates electricity that can be used by any of your household appliances, the power will heat your hot water via its standard element with no modifications required, once the hot water is heated the power can be used by any other appliance, therefore the power is not wasted.
With a solar hot water system the solar energy is used directly to heat the hot water via a roof top collector which has the hot water pumped through it. Once the hot water is heated in the tank the excess solar energy is wasted as it cannot be used for anything else. This system also involves more parts and a plumber as well as an electrician. Maintenance and repairs are generally much higher due to the greater complexity of the system.
So what size solar power system do I need?
The size of your solar system you need depends on how much power you use. Have a look at your power bill and find your annual usage in kWhs. (This is more accurate than the dollar value of your bill as charges vary).
Bearing in mind that solar power is only created during the day you will be using electricity from the grid in the evenings and overnight. A business operating during normal working hours or a retired couple at home during the day will make better use of the solar power then a couple who are both out at work all day.
You gain the most benefit by using as much solar generation as you can during the day because the price of power imported from the grid is always at a higher rate than what the power retailer will pay you for your exported power.
Control of loads (dishwasher, washing machine etc) that don’t need to be used at night, plus utilising energy efficient lighting etc. will further reduce power consumption from the grid at night. Note: line charges will still apply.
So as a guide:
If you are both at work full-time you will probably be able to replace 25% of your bill.
If one of you is at work, one at home or part-time plus children you will probably be able to replace 50% of your bill.
If you are both at home during the day you will probably be able to replace 75% of your bill.
|Size of system in kWs||2||3||4||5|
|kWhrs per year*||2,800||4,000||5,000||6,400|
*Figures are an estimated expected solar output based on average daily sunshine hours for Hawke’s Bay.
What other costs are involved?
Part of the process of installing solar is getting approval from your lines company (e.g. Unison) and connecting with a power retailer (e.g. Meridian) that is willing to buy your excess power. This means a meter that will read ingoing and outgoing electricity needs to be fitted. We do all the paper work to make these changes for you but the fees involved are determined by these companies and out of our control.
Current rules dictate that a 5kW installation is the maximum on single phase connections and 10kW on 3 phase connections, in domestic situations.
Note that for compliance, the installation must be documented and independently signed off by an Electrical Inspector which is included in our pricing. Some installations require an engineering report but no council consent is required.
Are there ongoing costs?
Solar power installations need to be serviced at least once a year, to check connections and terminations of the solar array and batteries if installed. The solar panels are generally self-cleaning with rain fall being adequate enough however additional cleaning maybe required in certain circumstances like coastal properties. We provide this service and can check any other concerns at the same time. Failure to take due care of your installation can invalidate warranties and cause systems to fail prematurely.
Will my solar system work in a power cut?
It is a common misconception that if you have a solar system, you will still have power in a grid failure.
If you have a grid tied system it will automatically shut down in the event of a power failure, this is a regulatory requirement to protect the people working to repair the power lines.
An off grid or hybrid system will not be affected by a power failure, as the batteries will keep the system working.
Click on the sun to see a live system in action
Hot water management system
A hot water management system (load controller) is another tool to help maximise the use of your solar power production. Once installed it can redirect your solar power to heat multiple sources of water e.g. normal hot water cylinder, spa pool, swimming pool, underfloor heating etc., thus enabling you to make maximum use of the solar power during the most productive time of the day; while you are at work and the children at school.
A load controller greatly increases efficiency to the extent that you can save a significant amount of money by installing a smaller solar system which is hugely beneficial when roof space is limited.