 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Windmills : Solar and Wind energy direct to element.
| Author | Message | ||||
| Fish Newbie  Joined: 28/01/2012 Location: South AfricaPosts: 18 |
Hi Anyone had a look at Solar(PV) and wind turbines connected directly to a load. What I had in mind is smaller voltage elements in my hot water system being driven by wind and the sun. Comments please. |
||||
Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Solar would be pretty easy, I guess, just connect it up and it will heat when the sun shines. But you would be much better off if you could use water heating panels instead of solar panels, much more efficient. Wind might be more involved. Windmills dont like a big load when they are starting up, they cant get into lift and run stalled ( slow, no power ). And they also need to be regulated at the top end, so they dont over speed and burn out the heating element. So you need a controller to let the windmill get up to speed, and to stop them over speeding. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
| Fish Newbie Joined: 28/01/2012 Location: South AfricaPosts: 18 |
Thanks Glenn I do understand your feedback; I had a friend that posed these questions to me and needed some clarity. In SA the price of electricity is set to sore, so we are looking at ways to offset this rising cost. I'm playing with an LG pan motor. Fish |
||||
| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
What sort of hot water tank do they have? Could you fit solar water heating panels to it? Recently I moved into a new place and I set up a 315 litre hot water tank. I had plans to use a couple of solar water heating panels, but to get me going, I used my generator to heat the water via the heating elements. I was amazed just how much energy it takes to heat up that much water. With the generator running for 3 hours, I had luke warm water! I guessed it was costing me something like $10 a day in fuel just to keep the water warm. That lasted a week, and I jerry rigged the solar water heating panels. Within a day I had abundant hot water, at no cost. Ever since then I havn't used the tanks heating elemets once. There was a few days of overcast weather a couple of weeks ago, so I had shorter showers, and still had luke warm water till the sun starting to shine again. You cant beat solar water heating, and its a very efficient process. The amount of energy a element heated water service uses is amazing, ok for the days past when electricity was cheap, but not in the future. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
| Fish Newbie Joined: 28/01/2012 Location: South AfricaPosts: 18 |
The system where he wants to be is totally free from the power utility. So he is going to put in solar system but came to see my wind Gen. to see if He could add it to his system so that it could assist the panels at night. I would love to stay in the wide open but the good half will not move, so I have brought the wide open to suburbia, neighbours don’t mind. Will chat again |
||||
Don B Senior Member  Joined: 27/09/2008 Location: AustraliaPosts: 190 |
Hi Fish, With regard to solar power for hot water, the problem is that solar photovoltaic panels are really quite inefficient. Some of the best might only convert 16 or 17 percent of the 1 kW per square metre or so of solar energy falling on them into electricity, and that is all that you have available to heat your hot water. Far better to have solar water heating panels that actually capture most of the solar energy that falls on them. Solar water heaters come in two kinds - the ones where the storage tank sits above the panels and heat flows in via natural convection currents, or the ones that have a ground mounted tank and a pump that circulates water through the panels via a small circulating pump. This last type needs a controller to shut the pump off whenever the water returning from the panels is not being heated, plus power to run the pump. You can certainly connect a wind turbine to a standard hot water system heating element, but these are usually of relatively high resistance, and only provide significant heating effect when supplied at mains voltage. They would do some heating when fed from a wind turbine, but I fear that the resulting showers would be very cool, and very brief. A good water saving measure though. Lower resistance elements would enable you to feed in more power from from your turbine, but have you enquired as to whether you can actually get them? While you can sometimes get a range of heat capacities that will fit, these will almost invariably relate to the mains voltage, and would in all likelihood be of much higher resistance than you need. The last point is that water heating takes a lot of power. You would need a very large PV array, and/or turbine, if these were to be the sole source of your water heating power. Regards Don B |
||||
Downwind Guru  Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
[quote]I would love to stay in the wide open but the good half will not move, so I have brought the wide open to suburbia, neighbours don’t mind.[/quote] To make energy and turn it into hot water is a very inefficient way to heat water, as Glenn has suggested, its far better to just use the sun to heat the water direct and store it in the current hot water system you have. If you use more than 200-300 liters of hot water per day then you have other issues to address first before trying to use solar or wind energy. The biggest part you can do before spending a rand on solar or wind is to learn to reduce your daily consumption of power and hot water. Solar and wind will never support a lifestyle, but it will teach you to adjust your lifestyle to live within your ability of lower consumption. This often dont mean major changes to life, just lots of little ones that all add up to big savings. Pete. Sometimes it just works |
||||
 Print this page |
