Thread: Renewable energy exploding

Er re dc/ ac. AFAIR China and other countries are now building lots of DC high voltage cables.
it seems Tesla was wrong.
regrds Philip A

I'm no pro on the subject. But from what I've been taught, and in summary...

Tesla was right, back then. AC allowed power stations to deliver across long distances. DC could not deliver. The AC transformer won it for Tesla.

Wind and solar supplies DC, few exceptions. We have DC lighting, DC gadgets and soon to be DC cars. And we can now deliver DC more efficiently on high voltage transmission lines.

So it looks like a DC grid would be the better option given the choice today. But AC was the right choice way back when.

Check on danskenergi.dk. Wind energy supplied 39% of generation capacity in 2014, 42% in 2015, 43% in 2017. The Danes are looking to 84% in due course.

Manic is correct. DC has advantages for a lot of uses, although they may be countered by advantages of AC for other uses. (for example, AC is much less prone to arcing and generation of spikes when switched.)

However, when it comes to transmission from one place to another, AC has the advantage that the technology to change voltage (transformers) already existed and allowed transmission over long distances at high voltage and low loss, and transform to the desired voltage for local distribution. The technology to change voltage like this for DC has only existed in the last two or three decades, and has probably only become more economical very recently.(If indeed it is)

Originally Posted by DiscoMick

We have a huge amount of gas and burning it halves emissions compared with coal.
I already have an estimate for the cost of going off grid - about $18k in our case. The longer we wait, the cheaper the batteries become. Maybe next year, after some other priorities.

I’m in the process of building completely off-grid. Off-grid suppliers still seem to be cowboy operations with little regulation. But you can find good suppliers.

It became and easy decision when off-grid vs connections was about the same cost, but obviously cheaper over time as I have no bills other than yearly maintenance.

It seems like new builds should have at least some solar & storage capacity built in.

Building decently energy efficient homes is another area where we could have impact. You can built 7+ star energy rated homes and not need much in the way of heating or cooling. Surely this is another way to reduce energy use without compromise to lifestyles.

Build a smaller house with some renewables capacity rather than a huge McMansion? But this requires a cultural shift in what we think of as a ‘good home’.

Yes, we're pretty poor at energy efficient design, and not just in houses either.

I was sitting in Coffee Club at The Hyperdome at Loganholme watching as the main automatic sliding doors remained almost permanently open, letting in 36 degree heat, as people walked in and out.
All it would have taken was to add a short passage with another set of doors and the heat entry could have been massively reduced. That would have significantly reduced the shopping centre's power bill to run its air-conditioning, and made it more pleasant for shoppers. But it's easier to just put up a poor design and the centre passes the extra electricity cost to the shopkeepers who add it to their prices, so the shoppers pay for poor design.

Another example is insulation. Many places have none. Most have a poor quality insulation because it's cheaper. Few have high quality insulation. We got some of the best stuff and put it in the ceiling and walls at Maleny and the difference was remarkable, both for heat and sound insulation. It has greatly reduced the need for aircon.

Not a clever country.

Tesla big battery is holding its own in a burgeoning energy storage market

Tesla big battery is holding its own in a burgeoning energy storage market | Giles Parkinson | Technology | The Guardian

The market for renewables is so skittish that Tesla offers its home battery with or without AC DC inverter for the same price. Yet change is inevitable. ‘Time-shifting’ is here.

The sooner we embrace the rapid shift to renewable energy the better for the planet and the sustainable supply of power post-fossil fuel. It’s been on the horizon for a long time. There’s no turning back.

I’m interested in building off grid in the next year.