What solar power system will suit my circumstances?
The average family household consumes between 20 and 30 kWh of electricity per day. A single person household can consume less than 10kWh per day. The rear of your electricity bill will often show your average daily consumption.
Please keep in mind that, if for example, you consume 5000 kWhrs at electricity a year and you install a solar system that generates 5000 kWhrs per year you will not be entirely bill free. The reason being that you will still pay for the electricity you use at night and during rainy days. The extra electricity your system generates during the day is generally given the lower rate (feed in tariff) and will not completely cover the cost of your night time electricity consumption.
The arrival of solar storage batteries has changed this paradigm when it comes to offsetting night-time energy use. Your capacity to store power in a battery is at the moment capped at sub 13kWh (nett 11kWh of storage). At current cost of power, ROIs are 12-15 years - about the life of high quality batteries. Prices however are dropping rapidly and storage capacity is increasing.
There are long term storage units in development that can store up to 1000kWh. They will enable you to store extra solar generated in summer to use in winter and on rainy days. However, they are currently cost prohibitive and large in size and so will remain so for the next 3-5 years at least.