Before you look at buying a Solar Hot Water System think about the freezing risk.
It might not be a concern in many areas but in Victoria, Tasmania and the colder parts of other states freezing conditions can damage cheaper systems.
What is the Problem?
The more basic systems have the water from the mains flowing through the panels and on to the storage tank, a direct system.
With a prolonged period of temperatures below zero the water can freeze.
As the water freezes it expands stressing the panels and pipes causing leaks.
What is the Solution?
The problem is well understood and can be solved by specifying an indirect system.
These systems use a different liquid to transfer the heat from the panels to the water in the tank, which is kept separate from the water going to your taps
This liquid may be water with an antifreeze additive or even water kept at a lower pressure.
There are two elements when considering Lighting levels for your new house.
Electrical Power (Watts)
Amount of Light (Lumens)
Watts
In the old days with incandescent bulbs it used to be simple, bulbs came in 40, 60 and 100watts and you were allowed up to 25 watts/square metre of floor space.
Now for your new build, in order to limit energy consumption, you are only allowed:
Indoors 5 watts /sqm (5W/sqm)
Outside 4 watts/sqm (4W/sqm)
Garages 3 watts/sqm
This doesn’t mean you have to have a gloomy house.
Modern light fittings such as Compact Fluorescent Lamp (CFLs) and Light Emiting Diodes (LED) give much more light than Incandescent Bulbs.
The above power consumption figure are for the initial construction. (After handover you can add additional lights)
Lumens
Probably the best way to think about lighting is to consider what task you are going to do.
Then look at how you will provide enough light in that area rather than the whole room.
Here are some suggested light levels for various tasks.
Under 10 lumens/sqm – Outside Security.
10-20 lumens/sqm – Conversation, Eating, Watching Television, General Circulation.
Its almost 2 years since I installed a solar power system on my current house.
The installation is 8 x 250 watt panels facing North and these 5 x 250 watt panels facing West.
Over the time they have been installed the amount generated has been:
North Facing panels – 5,164 kw
West Facing panels – 2,882 kw
Overall generation – 8,046 kw
Power production for each panel works out at:
648 kw for North facing panels
576 kw for west facing panels (89% of north facing panel’s production)
At first sight this seems to indicate that the North Panels are better value. . . . but there are a couple of reasons why this really isn’t the case.
When we are using electricity
Feed In Tariff (FIT) at 11.8 cents/kw is less than the tariff for taking power from the grid of 25cents/kw.
Time of Use
Generally we are mainly out during the day so apart from some use in the morning (before the solar system is generating power) our main actual use is from late afternoon.
The main use during the day is just the refrigerators and an hour or so of washing machine use 3-4 times a week.
We are home most evening; running air conditioning/heating, cooking meals and watching TV
Effect of Tariffs
Most of the power generated by the north facing panels will be going into the grid and only getting us 11.8 cents. . . . say 30% saving power and 70% going to the grid at 25 cents/kw.
So for each North facing panel the value of the power = 648 x 25 x 0.3 + 648 x 11.8 x 0.7 = $102.1.
With the West facing panel power its going to be more power being saved than going to the grid . . . . say 50% saving power and 50% going to the grid
So for each West facing panel the value of the power = 576 x 25 x 0.5 + 576 x 11.8 x 0.5 = $106.0 . . . . .MORE THAN THE NORTH FACING PANELS!!!
When I was growing up all the washing lines looked like this. . . . long straight nylon ropes.
Since then things have changed backyards have got smaller and some people don’t even have washing lines, everything goes in the tumble dryer
Well I think there are some good reasons why you should have a washing line.
Reasons for a washing line
Cost
A full cycle of a modern tumble dryer uses around $1 of power.
With just two of us at home now we would still do around 4 loads of washing a week. . . . That means tumble drying everything would cost around $200 a year.
Sustainability
As well as the cost there is also the sustainability aspect.
If the electricity from that full cycle comes from a coal power station it will release around 4kg of CO2.
Condensation
Unless you have got a venting kit you could be putting around half a litre of water into the air which can result in condensation problems.
If you start getting damp patches on the walls and ceiling mold can then become an issue.
Better Results
UV radiation from the sunlight kills bacteria and dust mites.
In addition nothing really beats the smell and feel of freshly air dried cotton sheets.
Less Wear Of Your Clothes
All that lint in the filter is the result of wear as the clothes rub against each other and the sides of the tumble drier drum.
Space
So how much space do you need?
The load from a typical front loading washing machine will take up around 10m of line, with a top loader it could be nearer 15m.
I would look at providing enough line for at least a couple of washes.
To get that amount of line in a typical backyard a good option would be a rotary clothes line (the traditional Hills Hoist) with line lengths ranging from 40 – 60m.
Limited on space? you could go for a wall, or fence, mounted rectangular folding frame which should give you around 20m of line.
Currently in Australia, there are just over 4000 electric cars on the roads.
They currently make up 0.1% of new car sales.
Having recently visited China I think that those numbers are going to change as I was amazed at the amount of electric cars and scooters I saw on the roads.
How much power is needed to charge an electric car?
Smaller electric cars have a battery with a capacity of 16 to 24 kWhours battery.
Larger cars such as the Tesla Model S have batteries in the 60 to 85 kWh battery.
Being ready for an electric car
Electric cars typically come with two charging options – slow and fast.
The slow charge option is the most commonly used as you will no doubt plug in at work or at home.
With a small car like a Nissan Leaf you can fully charge the car overnight at a rate of 2.5KW.
That means a simple 15amp socket in the garage will be adequate.
At the most it should cost a few hundred dollars.
If you think you might want a Tesla, or want to fully charge a small car in an hour or two you will need a special circuit and perhaps a 40 amp supply.
That could double the power supply to your house. . . . so you need to talk to your builder and their electrician at an early stage of your build.
The cost of a special charger and upgraded circuits could add $2,000 – $4,000 to your build costs,
I have been hearing a few discussions about Solar power where people are repeating myths. . . . . So here are four commonly heard myths and the truth.
MYTH
You must have a battery with a solar system
TRUTH
There is no requirement to have a battery. . . . If an solar salesperson tells you this he is trying to scam you and my advice is go elsewhere for your solar power system.
MYTH
Because of the low ‘Feed In Tariff’ you need a battery to make savings.
TRUTH
A battery cost a lot of money; so for the Tesla Powerwall you will be paying around $12,000 to save 40-50 cents per day. . . . . . A lot of the savings with solar power come from using the power you generate. As far as the feed in tariff is concerned as the panels are relatively cheap you can make great savings. At the moment my $4,500 system, without a battery, is saving me $634/year (check this post: Solar Power Update) almost 2 dollars a day.
MYTH
You need a large North facing roof.
TRUTH
These days panel prices have dropped so much that East and West facing panels can still be really effective. . . . .A further advantage is these panels generate much of their power in the morning and evening respectively which means you are more likely to be using the power rather than feeding the power into the grid. Over 35% of my panels face West.
MYTH
You won’t generate much power in winter.
TRUTH
Its surprising how much sun is around in winter that can help you generate power. . . . .For example in the five days before writing this post on 24th June 2018 my system generated over 30kwhrs of power
