Forgot to mention one of the best results of having an emergency home generator installed. When the power goes out, and everybody in the neighborhood has a dark and soon to be cold house, and the freezers all start to thaw, and you go over to the remote generator switch and push the button and the lights come back on again and your house stays warm and comfy and favorite television shows can still be watched! Well, you have become a hero to your wife, gaining good husband points that last, in a few cases, as long as *several days *after the incident! Worth every penny!!
[quote=“billfish678, post:13, topic:534650”]
[quote=“crazyjoe, post:12, topic:534650”]
What kind of crazy showers do you have in Ireland that use 2200W of power?
It’s an electric shower. It’s very common in Ireland to have a shower unit mounted on the wall of the bathroom, that heats the water on the way to the shower head. These are rated to 9A.
There are also pumped showers, as described by Really Not All That Bright, but the pumps would draw far less power than the heating element. My WAG would be of the order of 100W.
Domestic hot water (other than for the shower) is batch-heated in a copper tank by an “immersion heater”. This usually has 2 elements, the more powerful of which is rated to 3 kW. The hot water in the tank can also be heated indirectly by the boiler (U.S.: “furnace”).
Common usage in the US is ‘boiler’ if it heats water and ‘furnace’ if it heats air.
for the sake of nonUSA persons, in the USA
if you heat air (by burning fuel) for heating a building it is a furnace.
if you heat water for heating a building or powering a steam engine or turbine it is a boiler.
if you heat water for bath, shower and sink it is a hot water heater (which could get its heat electrically, by burning gas or indirectly from a boiler or other source).
Thanks kanicbird and johnpost for clarifying the terminology. I was referring to a boiler (fired with gas, oil, etc.) that heats water for the central heating system (radiators).
I’ve wondered about houses living along a fast moving stream or river.
Would a small water wheel (2 or 3 feet diameter) generate enough power for a house?
Heck a flywheel and magneto off a lawn mower could be rigged on the water wheel. At least that would be a place to start. I’ve seen bigger magnetos on small engines used in the oil fields.
It’s ironic that water wheels were used to power mechanical equipment for at least a thousand years. Then, they are forgotten when electricity comes along.
A water wheel sitting in a stream isn’t going to power a typical house.
You can dam up the stream and easily power a small house or a hunting cabin. Way back when I was in college, we had to design a system to do exactly that as part of our first year engineering courses. You can’t just dam up a stream these days though, even if it is on your property. You have to have environmental studies and all kinds of crap.
Water wheels haven’t been forgotten about at all. Hydroelectric power provides something like 6 or 7 percent of the US supply of electricity. Yeah, that’s small potatoes compared to nuke and coal plants, but we use a heck of a lot of electricity and there’s only so many rivers you can dam up.
What’s the difference between:[ol][]A hot water heater[]A cold water heater[*]A water heater[/ol]?
Florida Tech’s Botanical Gardens has a small Cyprus water wheel.
http://my.fit.edu/~fleslie/Conventional/Hydro/GardensWheel/waterwheel.htm
Wish I lived next to a stream. 
[quote=“Musicat, post:28, topic:534650”]
What’s the difference between:[ol][li]A hot water heater[]A cold water heater[]A water heater[/ol]?[/li][/QUOTE]
A “hot water heater” gets about 20 posts from dopers who insist that the word “hot” in there is redundant, unnecessary, and incorrect, and anyone who uses that phrase must be from some backwards Appalachian state. 
Go to backwoodssolar.com. On the left side of the page, under “Our Online Catalog”, is a box that says “Select a Product”. Click on that, and then from the list that ensues, select “hydropower”. This will take all the guesswork, personal opinions, and wild estimates out of the equation.