31
votes
Accepted
Why am I offered a 5 kW inverter with a 6.6 kW solar installation?
It could be that the system will spend such little time providing above 5 kW, once shading and losses are taken into account, that it's not worth the cost of getting the next-largest inverter.
...
- 14.8k
20
votes
Why am I offered a 5 kW inverter with a 6.6 kW solar installation?
Standard Test Conditions vs Real life
Photovoltaic panels are rated at "Standard Test Conditions" (STC):
Irradiance = 1000 W/m²
Cell temperature = 25°C
Air Mass = 1.5
Those conditions are achieved ...
- 301
14
votes
Why am I offered a 5 kW inverter with a 6.6 kW solar installation?
Solar systems are rated at peak power. It's normal for inverters to be rated less since you will very rarely have ideal conditions to reach peak power. For example, my inverter is rated at 80% of peak ...
- 241
12
votes
Accepted
Mismatched socks? What to do with hundreds of them?
Just about anything you would normally do with rags, but these ones are already in tube and bag form:
Use for washing, polishing and cleaning - just put your hand inside
Use to keep stuff in - small ...
- 425
11
votes
Domestic flywheel energy storage: how close are we?
Lets check the pros and cons on flywheel energy storage and whether those apply to domestic use (source):
Compared with other ways to store electricity, FES systems have long lifetimes (lasting ...
- 496
11
votes
Accepted
Is working from home a more sustainable choice?
Here's a piece of the answer for the U.S. Hopefully others can provide additional details covering other countries or regions.
MAJOR EDIT: Comments pointed out that something seemed fishy. I double-...
- 12k
10
votes
Domestic flywheel energy storage: how close are we?
Domestic flywheels are unlikely to happen for 3 reasons:
They must be heavy to store significant energy. If you need a crane to install one at your house it’s never going to be super cheap, even with ...
- 101
9
votes
What's the best way of getting an eco-friendly off-grid house?
I think you're right that building your own is likely to be necessary (we're in the same position). What I've discovered in Australia is broadly applicable in the global north, so:
An earthship can't ...
- 3,955
9
votes
Accepted
How much could the US reduce its electricity demand if people moved from Texas back to Ohio?
Original answer (which had a long explanation):
I proposed using degree days information to determine a baseload value for consumption of electricity and natural gas by region, and assume anything ...
- 12k
9
votes
Is heating with candles economically and/or ecologically worthwhile?
A related question was asked on SE Skeptics - Is this tealight-flowerpot heater more efficient than just tealights?
In the third answer, it is claimed the heat produced by one tea light candle is 0....
- 3,517
9
votes
Why am I offered a 5 kW inverter with a 6.6 kW solar installation?
There already are some answers addressing the fact that you probably will not reach or will rarely reach the rated power of your panels. That explains why you don't need a higher rated inverter. Now, ...
- 191
8
votes
How to reduce humidity in the home?
The outside relative humidity may be almost as high but the absolute amount of water held in the air is lower. So removing the most humid air is effective. That's the principle behind shower extractor ...
- 2,126
8
votes
What's the best way of getting an eco-friendly off-grid house?
I suggest that you question some of your assumptions.
Difficulties of off-grid.
Off-grid is HARD, and generally isn't worth it unless you are a long ways from the power lines. If you are looking at ...
- 7,247
7
votes
Accepted
Reusable alternatives to plastic wrap?
You don't need a perfect seal in the microwave - in fact the reason your plastic wrap doesn't explode is that the seal isn't perfect. So placing a plate or saucer on top of your microwave container (...
- 2,126
7
votes
Accepted
Environmentally friendly alternative to salt for de-icing walkways?
This is a question that many Departments of Transportation have struggled with as well! There are other chemicals that you can use, but all of them will have at least some impact on the environment. ...
- 306
7
votes
Domestic flywheel energy storage: how close are we?
We were looking into flywheel UPSes for my company and I read up on this a bit. Of note in recent developments:
Instead of traditional bearings, they're using magnetic bearings to mostly eliminate ...
- 71
7
votes
How to choose between an electric, natural gas, or heat pump clothes dryer?
You need neither a tumble dryer nor a drying cabinet. I haven't used either for years, and we are a two person household in a 36m² studio apartment in England (so winters are rather humid).
By far ...
- 2,659
6
votes
Accepted
For overnight heating, is it more efficient to use an electric space heater in a bedroom or a whole house natural gas furnace?
In terms of energy-efficiency within your own home (i.e. when we ignore energy losses outside the home), it will almost certainly be more efficient to use the electric space heater. It will be close ...
- 14.8k
6
votes
Why am I offered a 5 kW inverter with a 6.6 kW solar installation?
In some jurisdictions (like Flanders, Belgium), you have to pay a fee based on the maximum power your inverter can deliver to the grid.
As EnergyNumbers notes, slight undersizing won't necessarily ...
- 161
6
votes
Accepted
Any electric vehicle that can be used as a home energy storage?
You would need an EV that supports bi-directional loading, so that means one that uses the CHAdeMO charging system of Nissan and Mitsubishi. The CCS charging system that's popular in Europe and the US ...
- 14.6k
6
votes
Accepted
What is the most environmentally friendly way to paint/preserve wooden art or construction outdoors?
Our preferred solution here (on land and for seagoing wooden boats) is linseed oil based paints, or just plain (raw) linseed oil.
The oil soaks in the wood and therefore prevent water to soak into it ...
- 146
5
votes
What is the most sustainable way of making coffee?
TL;DR
Get your coffee beans with rainforest alliance certification
Drink it black or with non-dairy whiteners
Full answer:
I think the points you mention are relatively trivial compared to the big ...
- 358
5
votes
How to reduce humidity in the home?
I agree that at least a couple extractor fans or vents are a good idea, in both the kitchen and bathroom. (And does the clothes dryer vent outside?) Look into Heat Recovery Ventilators (HRV) and ...
- 306
5
votes
Being a sustainable Digital Nomad in a Van - First Steps
Three routes:
A: Your van has all your worldly possessions.
B: In addition you have a place you can store stuff.
C: Use a car towable R.V.
A: Everything is in your van.
Consider removing the ...
- 7,247
5
votes
Accepted
Are machine-washed rags more sustainable than paper towels for any & all household messes?
Your assumption seems to be correct -- consuming paper towels demands about eight times more energy than machine-washing and hang-drying reusable rags made from discarded textiles.
In order to ...
- 2,919
5
votes
Accepted
Temperature for hot water cylinder
Yes, higher thermostat temperatures mean more electricity consumption. Also your thermostat manual is right, bacteria growth is a valid concern.
The ideal conditions for the Legionella bacteria to ...
- 14.6k
4
votes
Reusable alternatives to plastic wrap?
My better half found a set of silicone lids. Three in the set, about 6, 8 and 10 inches across. They are heavy enough to stay put, and make a reasonable seal, an sticky enough that they don't slide. ...
- 7,247
4
votes
Accepted
Why should we bother to recycle household waste if it's only a small portion of all waste that is generated?
If 70 people recycle their waste, does that mean that the 71th person doesn't have to? The answer obviously is no, this person should recycle his/her garbage just like those other 70 people are doing. ...
- 14.6k
4
votes
better to heat house with gas or with electricity?
If you have access to electricity that comes from renewable sources (sun, wind, hydro, waves, biofuel) or from nuclear, then I would recommend getting a heat pump. Simply said a heat pump takes energy ...
4
votes
Accepted
What capacity solar system is required for new homes under the California 2019 Building Energy Efficiency Standards (Title 24)?
From Greentech Media's recent article, Everything You Need to Know About California’s New Solar Roof Mandate:
The solar mandate will be climate zone-specific and based on the floor area of the ...
- 12k
Only top scored, non community-wiki answers of a minimum length are eligible