I have a feeling that my water wouldnt be controlled externally ( by power company etc ) , cuz i get only one reading on the bill from one meter ( shown on right ) :
It means you pay less for hot water heating, but the power company turns it off if demand is very high.
Its common as dog poo, there's no real problem with it.
Hmmmm ok thats good to know. Well as of now the readings are looking stable, so thank goodness. I will keep monitoring this for next 2-3 days, and will report back !!
bfginger: There is not much point having gas hot water if you don't have mains gas available. Bottled LPG costs the same as electricity and is only suitable for gas cooktops or off the grid use. Mains gas costs depends on where in the country you are. It should be cheapest in Auckland. The daily charge is a big part of the cost so it is usually only cost effective to have mains gas for cooktops in the home if you also have mains gas hot water or central heating.
There are online tools to find out whether there is a gas mains outside your house but they won't tell if you if it's a few houses away. http://vector.co.nz/gas-estimator
Old electric cylinders are uninsulated and leak huge amounts of heat. You can buy a polyester cylinder insulation wrap for $50 which will soon pay for itself. Copper pipe insulation tubes can also save 10c of electricity per day.
The way they call instant heaters "geezers" overseas is confusing as they also call their water cylinders "geezers". Instant gas hot water should be around 10% more efficient than gas hot water cylinders but I doubt they last as long so the total cost may not be so different. Gas hot water cylinders can't have cylinder wraps around them for safety reasons so they need to be well insulated. The level of insulation on new cylinders varies.
There are water heat pumps from better brands available. http://heatpumpsauckland.co.nz/hot-water/ http://www.bosch-climate.co.nz/products-bosch-hot-water/renewables/compress-3000/compress-3000.html
Being on the right electricity plan will save you money. Plumbers may not be the best people to ask about the best choice of hot water supply. Every one I've known of is either fixated on the standard 180 litre electric or still thinks bottled LPG is cheapest. They're never interested in insulating pipes.
Not all plumbers are like that. Main thing is get a plumber who does both plumbing and gasfitting. As a plumber who doesn't have a gasfitting licence is not going to recommend a gas hot water system. Because they won't be able to install it themselves. Myself - Im a certifying Plumber and Gasfitter. So fully licensed for both plumbing and gas.
As for running costs - yes I do know what the differences are. (although the following is Auckland prices). If you have piped Natural gas then that will most likely have the cheapest running costs. (excluding solar during summer and wet back fireplaces during winter of course) Since Natural gas is around the 6c per kW/hr mark. And approx $360 per year in fixed fees. And most of the "Heat on demand" gas water heaters are approx 80% efficient. And 95% efficient condensing models are available. LPG supplied in the big 45Kg bottles is around the 16c per kW/hr mark. And approx $100 per year in fixed fees. So still cheaper than electricity in Auckland. Heatpump water heaters will never be as efficient as as heatpump room heaters. Due to the much larger temp rise required - approx 50deg. (5deg air temp, 55deg water temp) Compared to the temp rise on a room heating heatpump - approx 19deg. (5 deg outside, 24deg inside) So heatpump heaters are still cheaper than LPG and electric resistance. But unlikely to be cheaper than natural gas. As for night rate - The lines company (Vector) don't allow new night rate connections. So having your power with Flick electric is the closest you will get to night rate in Auckland. LPG in 9Kg bottles to too expensive to bother with except for very low usage situations. (Such as a gas hob only).
Also some heatpump heaters can only heat to 55deg. And they switch on the electric element ounce per day to boost the cylinder to 60deg for legionella (sp?) control. And there are also some that default to using the electric element when outside temps drop below 5deg.
Gas storage heaters are over 90% efficient if you get 1 of the Rheem stellar models. And the electronicly controlled "heat on demand" gas heaters like the Rinnai Infinity and Rheem Intergity. Have really good temperature regulation. (far better than those European type ones)
Install costs - to setup from scratch. Gas "heat on demand costs approx $2.5K for an easy install. So not much different to electric storage. Heatpump will probably be closer to $5K, So payback periods will be an issue.
Environmental - late night heated electric is definitely better than gas. But any heating during peak times - Gas is better than electric.As you will either be directly using fossil fuel power. Or power that would have displaced fossil fuels if you weren't using it yourself. Burning gas in a power station releases approx twice the CO2 compared to directly using the gas in your house for the same amount of end heat. (comparing gas to electric resistance heat)
sep11guy: I have a feeling that my water wouldnt be controlled externally ( by power company etc ) , cuz i get only one reading on the bill from one meter ( shown on right ) :
Based on the photo then I'd guess you're power bill is something like "All Day Economy"
If you had two meters or two separate reading on you're bill then you'd be "Anytime" & "Economy".
Being on "All Day Economy" means the power company provides a 24 general supply but is still able to control (turn off/on via the ripple relay) what is used by the HWC.
Depending on your consumption (if you're not at home most of day, turn off stuff you've not using, don't have kids, don't have energy-sapping appliances) if may be cheaper to be on "Anytime" & "Economy" rates.
Generally around 33% of you're "All Day Economy" consumption is hot water, but from you're observations before you can estimate roughly how much kWh your HWC is using.
Check your power company's website (or powerswitch) for a comparison of pricing between the two plans.
You can't have "All Day Economy" + "Economy" or you'd find that your normal house power would turn-off for a period of time during the night. Havoc ensues!
On a privacy-related note, from the photo I can see the serial numbers of both meter & relay. Using that information I could determine exactly where you live. (Disclaimer: I currently work for a power company & doing so without respect to a customer enquiry would get me fired)
The difference between LPG and electricity is the user charge must still be paid on electricity if we have gas but the LPG charge for the bottle service doesn't have to paid if we don't have gas. The $115/year fee can undermine the marginal c/kWh advantage to LPG. Depending on how much hot water and electricity someone uses and how efficient their system is there may be a slight advantage either way unless someone's usage patterns are unusual. Trustpower charges 17.64c kWh and Contact should be 5% cheaper if the Powerswitch website is to be believed. Contact has remade their website to be aimed at children so I can't see their pricing. The way electricity is charged is either with a large user charge or a token charge with the user charge tacked onto the kW/h price, effectively a subsidy for very low kWh users like sole pensioners. So a person may be able to save tens of dollars on LPG if they're a low electricity user as under that system their user charge is subsidised by other network users and so cutting electricity use reduces their hidden user charge too.
Electricity and electricity with supplementary systems like heat pumps and solar thermal have the advantage of being future-proofed for the arrival of affordable solar PV. With a timer or controller a tankload of hot water becomes very cheap.
Are you subscribed to our RSS feed? You can download the latest headlines and summaries from our stories directly
to your computer or smartphone by using a feed reader.
