Electric Boats

[gordmac]

EVs are not the solution, they are part of the solution. At 7k miles a year buying an EV doesn't make financial sense, for high mileage it maybe does.
Friends were looking at a secondhand EV. Never mind the capital cost, the cost of installing a charger was about a year of diesel!

 

[henryf]

I think you are overlooking the blindingly obvious. How can you possibly dare to even suggest that we put anything in the sea off our shores that could possibly disturb the poor innocent seahorses ?? Not only that but potentially blade like objects that they could hurt themselves on.

I can only hope that this thread isn’t seen by anyone from the seahorse trust or you’ll all be on a fizzer ?

How very dare you suggest I hadn't taken into account sea grass and sea horses. If you look at my plans you will see full provision is made to house and encourage Hippocampus habitation.

We have (genuinely) 3 trial habitats just in front of our boat monitored by the university of Portsmouth on a monthly basis. They even cover it with live CCTV cameras. Some of the stuff that goes on is a bit top shelf, these sea creatures are neither modest nor choosy. Any port in a storm....

Now that we've cleared that up. Oh and apparently they love the rumble of a pair of CAT C12 Acert lumps every now and again to get the juices flowing !!

 

[vas]

I've never seen tidal as a series of dams or barrages for the reasons you state. I've always seen it as lots of smaller turbines getting driven by tidal movement. Obviously water is massively more powerful than wind. Some sort of funnel to act as a multiplier and then turbines tethered to the sea bed. Think about solar power. A single panel doesn't put out that much but links lots together and it works. We have a lot of coastline, even a constant knot of tide is energy going to waste.

Henry

not my area, but are you sure you've seen tidal turbines and not wake (or whatever you call waves!) ones? I know (and was last week asked to help in engineering solutions) to some small wake turbines installed in breakwaters down here.
TBH, I don't consider the energy stored in water going up and down even 10m every six hours more than that stored in 1m wake going up and down every few secs

 

[Bigplumbs]

I think you are overlooking the blindingly obvious. How can you possibly dare to even suggest that we put anything in the sea off our shores that could possibly disturb the poor innocent seahorses ?? Not only that but potentially blade like objects that they could hurt themselves on.

I can only hope that this thread isn’t seen by anyone from the seahorse trust or you’ll all be on a fizzer ?

I know we absolutely must not disturb any wildlife while trying to save the planet. You are allowed to piss off Humans though cos they are obviously not part of nature

 

[vas]

I know we absolutely must not disturb any wildlife while trying to save the planet. You are allowed to piss off Humans though cos they are obviously not part of nature

hence why I'll stick to ICE until the EU (and your government) make up their mind in what is really the issue and how we solve it.
Current solutions are (imho) just bleeding edge for those that can afford it and/or are too keen on it.

tbh, I could possibly buy a Citroen AMI (seriously thinking about it!) but then I'll have to hack it to up the top speed to 80kph and change batteries to get it to do be able to do 120km in a "tank"

 

[Hurricane]

TBH, I don't consider the energy stored in water going up and down even 10m every six hours more than that stored in 1m wake going up and down every few secs

Are you sure?
The energy of water flowing in and out of the Bristol Channel must be enormous.
And it is predictable.
Wave energy, solar and wind are all dependant on weather conditions.

 

[vas]

post #190 and construction/silting Mike.
mind I'm not a civil engineer with specialisation in hydraulics/marine, but common sense prevails
from my decade living in the UK I don't recall sea being flat that often
Lots of smallish generators activated by floats going up and down according to the wake can produce lots of energy/electricity.
Wont harm the sealife, ever moving so sealife wont harm them, unobtrusive, smallish, works at night, what not to like?
Cost is minimal, installation fairly straight forward, delivery easy and local. You could have thousands of them all around.
Our (slow) lot are starting to consider it, but prefer to spend money buying imported (expensive) solar panels and fitting them everywhere atm.

 

[flaming]

Are you sure?
The energy of water flowing in and out of the Bristol Channel must be enormous.
And it is predictable.
Wave energy, solar and wind are all dependant on weather conditions.

Comes down to the cost / complication of extracting it. Currently the calculation is that it's better to have lots and lots of mostly fairly reliable wind power (in so much as it's very rare for it to be windless across the entire UK's array at the same time) than it is to have the tidal power.
I definitely agree that diversification is going to be more and more important as we get away from a fossil powered grid.

 

[Wing Mark]

Are you sure?
The energy of water flowing in and out of the Bristol Channel must be enormous.
And it is predictable.
Wave energy, solar and wind are all dependant on weather conditions.

The Severn Barrage concepts all come out a lot more expensive than nuclear. Lowest guess is about £160 per MWh, compared to 92 for Hinckley C.
Vague claims of meeting 5% of Uk electricity demand, but that's today's electricity demand not when we've all switched to heat pumps.
Biggest problem is that springs are 12m range at Avonmouth and neaps are only 5.
At best it's a very grandiose way to make managing the National Grid really difficult.

The other thing with tidal power is that nobody really knows what will happen if we start extracting serious amounts of power. How will it affect currents elsewhere, how will the seabed move long term etc etc.
If you reduce the amount of tide going up the Severn, will more go up the English Channel and flood Portsmouth?
Are we bothered?

 

[Croftie]

The other thing with tidal power is that nobody really knows what will happen if we start extracting serious amounts of power. How will it affect currents elsewhere, how will the seabed move long term etc etc.
If you reduce the amount of tide going up the Severn, will more go up the English Channel and flood Portsmouth?
Are we bothered?

Don't worry about that we are taking that much energy out of the wind that the earth will slow down its rotation then we all are dooomed.

 

[henryf]

not my area, but are you sure you've seen tidal turbines and not wake (or whatever you call waves!) ones? I know (and was last week asked to help in engineering solutions) to some small wake turbines installed in breakwaters down here.
TBH, I don't consider the energy stored in water going up and down even 10m every six hours more than that stored in 1m wake going up and down every few secs

The problem is wave generation requires wind which is already captured and isn’t anything like as constant or predictable.

4 times a day 365 days a year with only a modest slack period in between. When it’s slack somewhere the tide is running elsewhere…..

By “I’ve never seen tide generation as” I mean in my mind when thinking about the concept rather than physically with my eyes.

 

[Wing Mark]

There used to be a lot of tide mills about.
Emsworth.
Chi Marina.

Chi Marina current looks like a lot of power when it's not on your side, but it's not many watts in the scheme of things.

 

[henryf]

There used to be a lot of tide mills about.
Emsworth.
Chi Marina.

Chi Marina current looks like a lot of power when it's not on your side, but it's not many watts in the scheme of things.

You say not many watts, I wonder? How much power would it take to pump all that water? A significant number and certainly enough to power the immediate area. It’s a question of efficient harvesting. Think about oil, once the low hanging fruit of oil that is gagging to come out the ground is mined engineers start using some very clever tricks to pick the bones. We need to do the same with tide.

But you’re right, this is not a new concept. Water once powered our industry.

 

[jrudge]

The challenge I have with ev is paying more ( lots more ) for a product that introduces hassle to my life.

In practice I don’t do many miles. In practice I will charge at home. It will however cost me a lot more to buy and when I do long distances ( 3-4 times a year ) it is hassle I don’t need.

Rapid chargers according to articles I read a while ago can be very expensive to use. Same cost per mile as petrol.

I was living in Bosham for 5 weeks last summer. House had no parking, use the car park at the back on a permit. Only a mom walk from the house but no power. I went to London to collect and drop my kids multiple times. Ev. I would have been bugggered.

Just been round Norfolk with my kids. No chargers anywhere we stayed.

If the ev is 30% cheaper I will put up with the hassle. But it is 30% more - so I won’t

 

[julians]

The challenge I have with ev is paying more ( lots more ) for a product that introduces hassle to my life.

In practice I don’t do many miles. In practice I will charge at home. It will however cost me a lot more to buy and when I do long distances ( 3-4 times a year ) it is hassle I don’t need.

Rapid chargers according to articles I read a while ago can be very expensive to use. Same cost per mile as petrol.

I was living in Bosham for 5 weeks last summer. House had no parking, use the car park at the back on a permit. Only a mom walk from the house but no power. I went to London to collect and drop my kids multiple times. Ev. I would have been bugggered.

Just been round Norfolk with my kids. No chargers anywhere we stayed.

If the ev is 30% cheaper I will put up with the hassle. But it is 30% more - so I won’t

yep, its not currently mature enough (IMO), it will get there though. I'll stick to my M4 for now.

 

[Bigplumbs]

The challenge I have with ev is paying more ( lots more ) for a product that introduces hassle to my life.

In practice I don’t do many miles. In practice I will charge at home. It will however cost me a lot more to buy and when I do long distances ( 3-4 times a year ) it is hassle I don’t need.

Rapid chargers according to articles I read a while ago can be very expensive to use. Same cost per mile as petrol.

I was living in Bosham for 5 weeks last summer. House had no parking, use the car park at the back on a permit. Only a mom walk from the house but no power. I went to London to collect and drop my kids multiple times. Ev. I would have been bugggered.

Just been round Norfolk with my kids. No chargers anywhere we stayed.

If the ev is 30% cheaper I will put up with the hassle. But it is 30% more - so I won’t

You got that all Spot on but you forgot to mention the time you arrive home and it is raining and you are tired and just dash into the house and forget to plug in. Next morning you have a useless car with a flat Battery. These are all real world things that many people like to bush over

 

[Mistroma]

You say not many watts, I wonder? How much power would it take to pump all that water? A significant number and certainly enough to power the immediate area. It’s a question of efficient harvesting. Think about oil, once the low hanging fruit of oil that is gagging to come out the ground is mined engineers start using some very clever tricks to pick the bones. We need to do the same with tide.

But you’re right, this is not a new concept. Water once powered our industry.

Bit of thread drift but harvesting tidal energy is the problem. Water is about 1,000 more dense than air and you can therefore extract around 1,000 more energy for the same flow rate. However, the flow rates are much lower. I seem to remember that the tidal wave propagates around UK at about 60mph but it's the rate of rise and fall that determines flow past a turbine. You can build tidal stream farms like wind farms or a barrage or large artificial lagoons. They all have pros and cons. e.g. Wind turbines need to withstand freak storms, sub-sea water turbines have a much more predictable flow rate.

I remember reading a figure of about 11 kWh/day per person in the UK from all types of tidal power combined. Unfortunately, the investment and infrastructure required would be vast and isn't going to arrive any time soon. As you say, low hanging fruit will be taken first and I'd guess that to be more like 1kWh/day per person in UK.

EDIT: I've just checked and found a figure of 250GW as the average total tidal energy arriving at UK (North & South ends). That's close to 100kWh/day per person in UK. Certainly a lot but I think my guess of extracting 1% of this theoretical amount is probably very optimistic.

 

[henryf]

Bit of thread drift but harvesting tidal energy is the problem. Water is about 1,000 more dense than air and you can therefore extract around 1,000 more energy for the same flow rate. However, the flow rates are much lower. I seem to remember that the tidal wave propagates around UK at about 60mph but it's the rate of rise and fall that determines flow past a turbine. You can build tidal stream farms like wind farms or a barrage or large artificial lagoons. They all have pros and cons. e.g. Wind turbines need to withstand freak storms, sub-sea water turbines have a much more predictable flow rate.

I remember reading a figure of about 11 kWh/day per person in the UK from all types of tidal power combined. Unfortunately, the investment and infrastructure required would be vast and isn't going to arrive any time soon. As you say, low hanging fruit will be taken first and I'd guess that to be more like 1kWh/day per person in UK.

EDIT: I've just checked and found a figure of 250GW as the average total tidal energy arriving at UK (North & South ends). That's close to 100kWh/day per person in UK. Certainly a lot but I think my guess of extracting 1% of this theoretical amount is probably very optimistic.

This is a long game not a quick fix. The speed at which politicians are trying to enforce change means that manufacturers are jumping on bandwagons and no one is really thinking about the long term future which is ironic given it's the long term future that we are trying to protect.

I see tidal power as a 10 - 20 year journey. Once in place providing the moon stays in position we have eternal "free" electricity on a highly predictable basis. If the world depended on it we could have reliable tidal power in under 5 years but let's set a 10-20 year target. It will also be self financing which is great, people are accepting paying a lot of money for electricity which means a valuable prize at the end of the project.

Thanks to the emphasis on wind and solar tidal energy seems to be a bit of a cottage industry led astray by white elephant dead ends like wave generation.

 

[Wing Mark]

You say not many watts, I wonder? How much power would it take to pump all that water? A significant number and certainly enough to power the immediate area. It’s a question of efficient harvesting. Think about oil, once the low hanging fruit of oil that is gagging to come out the ground is mined engineers start using some very clever tricks to pick the bones. We need to do the same with tide.

But you’re right, this is not a new concept. Water once powered our industry.

Let's see.
How big is the pool? let's guess 1km square for easy numbers.
Let's guess you can get the energy from that water falling 1 metre.
That would be a volume something like 2m x 1000m x 1000m = 2 million tonnes (2x 10^9 kg) weighing 2x10^10 N x1m = 2x10^10 J in 6 hours or 6 x 60x 60 seconds, roughly 2 x 10^4 seconds.
That's about a megawatt. Roughly the electrical needs of about 1200 houses, if they're only using electricity for lighting and TV and stuff, not heating.
I don't think Chi marina is quite that big, just a long walk if you're carrying a case of beer?

Water did indeed once power our industry, then we invented the steam engine, and most people stopped playing with water wheels and windmills.

 

[John100156]

Let's see.
How big is the pool? let's guess 1km square for easy numbers.
Let's guess you can get the energy from that water falling 1 metre.
That would be a volume something like 2m x 1000m x 1000m = 2 million tonnes......

If it falls 1m, surely that's 1 million tonnes..?