Browse Forums Eco Living 1 Sep 04, 2010 9:06 pm I'm about to install some solar power panels. The aim is to "poverty proof" us for our old age, as power is going to be damn expensive in future. There are two of us most of the time, but there can be two more staying in the house for short periods. We have all the usual appliances plus ducted air con in a four bedroom house. We have solar hot water. My question is : how many kilowatts do we need to install? I'd appreciate any opinions. Re: Solar power - how much do I need 2Sep 04, 2010 9:23 pm its more complex than just installing solar units. To run a house you will need to not only have panels but deep cycle batteries to store the energy. I assume your talking about being off the grid? Also panels deteriorate. They have a half life of about 10 years. Most houses burn 10-20 kwhours per day. But the issue is RMS power eg. to kick start fridges and cooling units. For demand purposes you would need about 2.5kw on demand at a minimum. This means to build self-sufficiency you will need an outlay of about $50-80K plus refurbishment every 5 or so years. Re: Solar power - how much do I need 4Sep 04, 2010 9:32 pm well most basic appliances electrical will create a demand of up to 1 - 1.5kw. However an electric kettle etc. will be 2.4kw on demand. You need to do an audit of what you require to run. Unfortunately your roof will only hold so many panels meaning batteries will be required for peak demand. Re: Solar power - how much do I need 5Sep 04, 2010 11:07 pm Hi Jassy, Trying to determine the size of the system you need is really very dependant on your current energy use. I'd check your electricity bills to see if they show a average daily usage. My account (from Synergy in WA) shows we use between 15 - 20 Kw a day. The quotes we got on our 1.2Kw grid connected system suggested that we'd generate around 5Kw a day during winter, and up to 7Kw a day in summer. We are generally generating around 5 - 6 Kw a day at the moment. Just as a side note, grid connected systems don't require battery banks. We also have a neat little tool installed called a Cent-a-meter. It shows you how much energy you are using at any given time. It's not related to the power generation, but it is useful to get an quick and easy idea on what energy you are using at any given time. I feel that this is the big benefit of a system like this is that it makes you think more about your energy use and continually try to reduce your use for each day. Good luck with your installation, at any rate. Thanks, Chris Re: Solar power - how much do I need 7Sep 05, 2010 2:46 pm As suggested you need to check your electricity bills over the last year and work out an average kiloWatt Hours (kWh) per day. Then read this from the Your Home Technical guide site - http://www.yourhome.gov.au/technical/fs67.html - the section about half way down on Siting. For Grid connect system use the annual average daily peak hours of sunlight. A 1 kW(peak) grid connected system should generate that number of kWh per day on average - though as suggested in the annual production table this should be factored down a bit to allow for inverter and other system losses. Of course that is rough estimate - will depend on system and location - and whether you have the appropriately oriented roof to fit the system. You may find that economically it pays to reduce usage as much as possible first. So things like changing light bulbs to CFL or LED. If your refrigerator is more than ten years old it could be replaced (and downsized if possible) - fridge efficiency has improved greatly of recent times - check the annual energy usage figures next time you are in a fridge store. Off course turn off additional fridge (if possible). You have ducted aircon so ensure your insulation is up to scratch and seal draughts - zoning of house heating - ensure that sun is blocked from hitting the windows in summer - etc. (The rest of the Your Home technical guide provides good guidance for this - http://www.yourhome.gov.au/technical/index.html.) Re: Solar power - how much do I need 8Sep 05, 2010 2:55 pm Eccles is right. The most cost-effective way is to reduce consumption before sizing your system. Heating the home and heating water uses up to 2/3rds of your energy. A 4 person solar HWS offsets as much energy as a 1.5 kW PV system. Would also like an opinion from anyone that has used xcem over hebel for floors. Thanks 1 13279 2 15459 Our relationship with the owner is good, but I'm not sure if I want to impose putting a pole on their property. Your conversation with your neighbour must have gone well… 4 9304 |