Some truth to people who think we can be 100% renewable

[Alan]

Brutal, brutal environment for longevity and maintenance.


There are also impacts to sea life. But the engineering for durability tends to be the biggest stumbling block.

Indeed, that’s why it has been talked about for decades but there are now some projects in the pipeline. The Scottish Government has approved a project to build a 10 megawatts array.

Islay Tidal Energy Scheme

 

[samclem]

Brutal, brutal environment for longevity and maintenance.

I thought I'd seen some concepts that used a (conceptually) simple tethered bouy. On the tether line was a linear electromechanical generator, the bouy pulled magnets past the coils. So, no seals needed for rotating shafts, etc. I'm sure it would affect some type of migrating animal and would be a hazard to navigation, but it seemed like it might survive the sea, for awhile. A lot of things that look great in a Popular Mechanix blurb don't look so great in real life.

 

[explanade]

I visited the Great Ocean Road last year, where the Twelve Apostles are.

The tidal intensity creates the rock formations and then tear them down, build them back up again, over a long period.

Wondered about them putting windmills offshore but it may ruin the views of a huge attraction.

I didn't see windmills until I'd driven some distance inland, north towards The Grampians.

You see a lot of offshore windmills when you're flying into Amsterdam so maybe offshore wind farms for the UK? More if they already have them?

 

[NW-Bound]

I remember reading about harnessing tidal and wave power for electricity generation in Spectrum (an IEEE magazine) back in the 70s, and the idea probably surfaced decades earlier. Wind and solar generation turned out to be a lot easier.

And by the way, Spectrum also had an article about something the same as the Hyperloop now proposed by Musk. Conceptual ideas are easy. Actual engineering implementation is hard.

Remember the photo I linked earlier about the early derelict windmills in California near Indio and Palm Springs. They failed so quickly after installation that whenever I drove through the area in the early 80s, there was only about 1 in 20 with blades rotating. Somewhere, I read that dust and sand storms took out bearings and gearboxes. And the strong wind made maintenance difficult.

I like solar. Clean and no moving parts. The problem is that the sun does not shine long enough. Well, if there were more sunshine, it would be even hotter, and the extra power would not be enough to keep me from roasting. You can't win.

 

[Alan]

I visited the Great Ocean Road last year, where the Twelve Apostles are.

The tidal intensity creates the rock formations and then tear them down, build them back up again, over a long period.

Wondered about them putting windmills offshore but it may ruin the views of a huge attraction.

I didn't see windmills until I'd driven some distance inland, north towards The Grampians.

You see a lot of offshore windmills when you're flying into Amsterdam so maybe offshore wind farms for the UK? More if they already have them?

Lots of offshore windmills in the UK including one offshore close to where we live. 33 offshore farms according to this list, and I do see our local wind farm listed.

http://www.early-retirement.org/for...am-be-around-next-week-99626.html#post2288905

 

[jimnjana]

NWbound, any advice on mini split options? Looking into one for master bedroom and larger one for main living area. Have a 12kw PV system in central Florida. Don't know if the DIY route will be for me. We have net metering DW recently moved portable ac out of master and now leaving whole house ac at 78 24 hrs a day .

 

[misanman]

NWbound, any advice on mini split options?

I'm also interested in mini splits for our cottage and need to get educated. Maybe this should go into a thread of its own?

 

[MichaelB]

NWbound, any advice on mini split options? Looking into one for master bedroom and larger one for main living area. Have a 12kw PV system in central Florida. Don't know if the DIY route will be for me. We have net metering DW recently moved portable ac out of master and now leaving whole house ac at 78 24 hrs a day .

I'm also interested in mini splits for our cottage and need to get educated. Maybe this should go into a thread of its own?

There is some discussion here http://www.early-retirement.org/for...n-a-frog-finished-room-over-garage-99124.html


Otherwise you might want to start a thread on that, here it'll probably get lost.

 

[NW-Bound]

There is some discussion here http://www.early-retirement.org/for...n-a-frog-finished-room-over-garage-99124.html

Otherwise you might want to start a thread on that, here it'll probably get lost.

Yes, I talked quite a bit about my experience with the self-installed mini-split in that thread.

If someone likes to know about how to install one himself, I will volunteer what I know.

 

[ERD50]

When brownouts and blackouts are a daily occurrence, people will consume less energy by default.

I will be able to keep cool ....

With so much of the South dependent on A/C, I'm surprised I don't hear more about the process of making ice all night/off-peak, and using that to help sink heat from A/C units during peak hours.

This might be hard to do at the residential level, but are large installations doing this? It's analogous to your storage battery, just storing 'cool' instead.

-ERD50

 

[NW-Bound]

My former megacorp had multiple buildings on a campus. They had a central cooling plant, and pumped cold water to the office buildings. I don't know how much cool water they could store.

An earlier megacorp used an evap cooler to cool the outside air to help the AC condenser. This precooler concept was used for residential ACs for a while in the 1980s, but discontinued because of the maintenance involved that home owners did not want to deal with. When you have to call an AC guy for any minor thing, all the electricity saving is gone in no time.

 

[ncbill]

With so much of the South dependent on A/C, I'm surprised I don't hear more about the process of making ice all night/off-peak, and using that to help sink heat from A/C units during peak hours.

This might be hard to do at the residential level, but are large installations doing this? It's analogous to your storage battery, just storing 'cool' instead.

-ERD50

I saw one article on that approach over a decade ago...but the minimum size was 5 tons (too big for most residential applications)

I've wondered if it would be cheaper for S. California residents facing Tier 3/4 power charges to install natural gas chillers instead of conventional air conditioning.

 

[NW-Bound]

Natural gas chillers are not practical for residential usage. And is there an adequate supply of natural gas to California?

It would seem to me it makes more economic sense to use natural gas in power plants, then send electricity to the end users. It is easier to string wires than to bury gas pipes.

California is starting to ban natural gas anyway, as reported in post #528.

 

[HFWR]

The US produces roughly 4T kWh of electricity annually, and uses the equivalent of 4.7 T kWh of gasoline annually. Thus, electricity production will have to more than double to eliminate gasoline as a motor fuel.

I’m sure someone will check my handiwork...

 

[catii]

Numbers are about right, but even states like Hawaii, where we're going to 100% renewables, don't address gasoline & aviation fuels as part of that conversion.

 

[NW-Bound]

Don't forget what people burn to stay warm in the winter. People burn a lot of natural gas to stay warm, in the US as well as in Europe.

 

[explanade]

They don’t have to convert that gas all at once. It will take decades.

 

[NW-Bound]

Nobody knows how to do that now, anyway.

Gotta to replace the existing thermal and nuclear plants and the cars first, and that is hard enough.

 

[HFWR]

They don’t have to convert that gas all at once. It will take decades.

I concur, though I believe the idea of eliminating fossil fuels within the next three decades has been floated by a major candidate. While their heart is in the right place, I suppose, I don’t believe we’ll be ready, willing, and able to do that...

 

[NW-Bound]

Going to 100% RE is a lot easier if people consume less energy than they do now. Try to tell that to people, that they should live in smaller homes, drive smaller cars. Hah!

I read recently that Musk complained about Singapore not supporting EVs, such as not building or allowing more charging stations, etc... The Singapore minister in charge of resources said that the solution was more public transportation. He said that EVs are just a lifestyle which they cannot support. There you go!

And then, some will point out that reducing consumption will result in job loss. Germany is worrying right now that EVs replacing ICE cars will result in a lot of jobs getting eliminated. Can the workers be redeployed in factories making lithium batteries? Unfortunately, lithium batteries cannot be made by hand, and the production is mostly automated. People who have money to invest in technology will be richer, while the workers will be poor. Say hello to more income and wealth disparity.

 

[meierlde]

Don't forget what people burn to stay warm in the winter. People burn a lot of natural gas to stay warm, in the US as well as in Europe.

of course there are heat pumps which are said to work in the Yukon(which demonstrates that the tradition heat pump which puts out less heat the colder it gets can be modified. Note that rural natural gas is not a common as urban natural gas, they use propane since it does not require pipelines. Also a big problem with elecric cars is that turning the heater on drains the battery faster. (Heaters on fossil fuels cars use waste heat). With a demand curve like that in Ca you could have a tank of hot water that is heated during time of minimal demand to provide heat at times of max demand. Moving to electric heat will likely create a new demand peak around 7 am as folks wake up and turn up the heat.

 

[JoeWras]

Moving to electric heat will likely create a new demand peak around 7 am as folks wake up and turn up the heat.

True. In far S. Florida, there were some mega cold snaps in the 70s and 80s.

There were brownout and overload problems at just the time you mention. All heat down there was (is) just electric resistance heat, which can put a load on real quick.

 

[NW-Bound]

When it gets down to -50F (-46C) in Fairbanks, Alaska, I wonder if there's any heatpump that can work. And then, where's the electricity to run these heat pumps?

Even in the continental US, we will be hard pressed to generate power in the winter, where solar production drops to nothing in many locations. You can blanket the SW of the US with massive solar farms to transmit it up north, but in other seasons you have unused capacity.

The technology is one thing, whether something is economical is a much harder thing to achieve.


PS. Both of my homes are all electric, including the boondocks home at 7,000 ft. The coldest I have seen was -10F. The heatpump still runs, but the thermostat kicks on the backup internal electric resistance heater when it senses that the output is not warm. There are 2 levels of resistance heating, and the thermostat will switch gear as appropriate.

I kept my home at 45F whether I was there in the winter or not. The full-timers living there all have propane heating.

 

[ncbill]

New homes built here in the mountains have both electric resistance strips & propane furnaces as backup to the (EDIT: standard air-source) heat pump.

Of course, another advantage to having propane is to run a generator during power failures.

 

[Ed_The_Gypsy]

When it gets down to -50F (-46C) in Fairbanks, Alaska, I wonder if there's any heatpump that can work.

I know of one heat pump at a private home that had a water loop down in the ground. The earth gets warmer the deeper you dig. You have to take into account that heat transfer through earth ain't real great. It must be calculated to be sized right. You can't SWAG it.