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blackrose

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I'm still intending to fit solar panels, but if I'm honest due to work and life, my boat spends 95% of the time at its mooring connected to shore power. 

 

When I'm here I use a mains immersion heater in my calorifier to heat water for an hour twice a day. Electricity prices are set to rise of course, but if fitted panels and unplugged from shore power I'd have to use diesel to heat water either from my engine or Webasto which might be more inefficient and expensive, so is there any point? 

 

On the other hand I could just switch to mains to heat water for an hour or two/day while using the panels/inverter to run the rest of my low power mains appliances and the 12v system. Would that make sense? 

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Loddon is set up so that shore power comes in and splits to the Combi and the other leg goes to the immersion and washing machine.

This means I can turn the AC feed to the combi off and leave it running on Solar/batteries  meaning  the WM/Immersion is not run from the batteries.  

I can switch the WM/Im to run off the combi/batteries but only do that when I need to do some washing whilst away.

All legs are protected by the correct value mcb/rcbo  it wasn't difficult, but I do have 2 small consumer units and a C/O switch to make it happen.

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Yes I suspect your AC system is a tad more sophisticated than mine. I basically have a single mains ring. 

2 hours ago, Tracy D'arth said:

Shore electricity is the cheapest option and will continue to be so.

 

Ignoring the cost of panels, etc, and accepting that it's not sensible to run high power mains appliances from batteries, shore power can't be cheaper than free electricity from the sun can it? 

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A lot will depend on what price you pay for your electric surely?

 

 If you pay a unit cost and a, daily standing charge cost, as we do, it makes sense to find alternative means.

 

From what you say, though it sounds as if you don't. 

 

For us, that means using a gas water heater  and solar panels to cover all our other needs (except for the washing machine). 

 

You could consider using solar for water heating too, but that will only get you so far, obviously. 

 

For us,  every KWh saved is a bonus, and the more days we don't plug into a shoreline, the more we save. As the daily plug in charge outweighs the unit cost, it makes sense.

 

I did the calculation once for gas v electric water heating years ago. There wasn't much in it (for us)  at the time, though things may well have changed now. 

 

Whatever you do, short of jumping in the River to wash is gonna cost. 

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13 hours ago, blackrose said:

I'm still intending to fit solar panels, but if I'm honest due to work and life, my boat spends 95% of the time at its mooring connected to shore power. 

 

When I'm here I use a mains immersion heater in my calorifier to heat water for an hour twice a day. Electricity prices are set to rise of course, but if fitted panels and unplugged from shore power I'd have to use diesel to heat water either from my engine or Webasto which might be more inefficient and expensive, so is there any point? 

 

On the other hand I could just switch to mains to heat water for an hour or two/day while using the panels/inverter to run the rest of my low power mains appliances and the 12v system. Would that make sense? 

 

Equipping your boat initially will play havoc with your budgeting. I think solar panels are a good way to go for generally having an alternative, to augment what you have, in as far as they can manage with our grey skies, But you haven't mentioned whether you have an instant on-demand hot water boiler of any sorts; a Morco or something. I run the older Paloma. I would change to a modern Morco, but am told the gas pipe would all need changing, as the Paloma's wouldn't be capable - not able to handle the demand of a Morco. 

 

 

Edited by Higgs
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59 minutes ago, rusty69 said:

You could consider using solar for water heating too, but that will only get you so far, obviously. 

It had some up front costs, but my solar thermal hot water system means that my running costs for hot water for half the year are zero. For the other six months, the stove back boiler means that I also get hot water as a by product from what is for many land based people the now impossibly expensive act of staying warm. I did fit an immersion heater in the calorifier, but never used it. Had to replace the cauliflower after the first one sprang a leak (no expansion tank). Didn't bother fitting an immersion heater to the new one.

These days, with solar panels being so cheap, compared with fifteen years ago, when I planned my boats systems, it would be worth investigating using an immersion heater as a dump load for excess power once the batteries are fully recharged each day in summer, rather than solar thermal.

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14 minutes ago, Jen-in-Wellies said:

It had some up front costs, but my solar thermal hot water system means that my running costs for hot water for half the year are zero. For the other six months, the stove back boiler means that I also get hot water as a by product from what is for many land based people the now impossibly expensive act of staying warm. I did fit an immersion heater in the calorifier, but never used it. Had to replace the cauliflower after the first one sprang a leak (no expansion tank). Didn't bother fitting an immersion heater to the new one.

These days, with solar panels being so cheap, compared with fifteen years ago, when I planned my boats systems, it would be worth investigating using an immersion heater as a dump load for excess power once the batteries are fully recharged each day in summer, rather than solar thermal.

To clarify, I was referring to solar thermal, not using PV and immersion as a dump load. 

 

Though, as you say, with the relatively low cost of PV, maybe solar thermal is no longer worth considering. 

 

When I dabbled with solar thermal, I got all the bits off ebay for less than 100 quid. It was a moderate success. I just wish I had paid 5 quid for some antifreeze,otherwise, I might still have a working system. 

 

Doh. 

 

Eta. I seem to recall @blackrose has a Morco gas water heater 

Edited by rusty69
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I could probably make better use of the back boiler in the Morso. It's thermo syphon, but I could fit a pump and circulate it around the second coil of the calorifier.  The back boiler system came with a pump, when I bought the boat. When I removed it, because of the noise, I found out why it was there in the first place. Something is not quite right with the installation, and the lower part of the radiators don't heat up thoroughly. 

 

 

Edited by Higgs
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4 hours ago, rusty69 said:

A lot will depend on what price you pay for your electric surely?

 

 If you pay a unit cost and a, daily standing charge cost, as we do, it makes sense to find alternative means.

 

From what you say, though it sounds as if you don't. 

 

For us, that means using a gas water heater  and solar panels to cover all our other needs (except for the washing machine). 

 

You could consider using solar for water heating too, but that will only get you so far, obviously. 

 

For us,  every KWh saved is a bonus, and the more days we don't plug into a shoreline, the more we save. As the daily plug in charge outweighs the unit cost, it makes sense.

 

I did the calculation once for gas v electric water heating years ago. There wasn't much in it (for us)  at the time, though things may well have changed now. 

 

Whatever you do, short of jumping in the River to wash is gonna cost. 

 

That's right, I don't pay a standing charge and at the moment I'm still only paying 20p/kWh but that's set to at least double shortly. You pay a standing charge only when you plug in? That's unusual, I thought most people who pay a standing charge paid all year round just for having the bollard. So in your case they monitor which days you connect to shore power?

 

I have a gas water heater but I can't imagine using gas to heat water is going to be any cheaper than electricity, even when the electricity cost goes up. 

 

The point for me is that if I'm going to switch over to shore power every time I want to run a high power mains appliance like the immersion or washing machine, that means the solar panels/batteries/inverter would only be used for things like AC table lamps (with energy efficient bulbs), mains TV, and a few other things + the the 12v system, all of which amounts to minimal use of electricity anyway when compared to the power demands of the immersion & washing machine. So I'm struggling to see the point of the panels. It might take decades to recoup the installation costs.

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7 minutes ago, blackrose said:

 

That's right, I don't pay a standing charge and at the moment I'm still only paying 20p/kWh but that's set to at least double shortly. You pay a standing charge only when you plug in? That's unusual, I thought most people who pay a standing charge paid all year round just for having the bollard. So in your case they monitor which days you connect to shore power?

 

I have a gas water heater but I can't imagine using gas to heat water is going to be any cheaper than electricity, even when the electricity cost goes up. 

 

Yes(though it may not be called a standing charge, it is a fee for plugging the cable into the bollard), and yes.

 

As I said, for us, it makes sense to use gas to heat the water in the summer months. Though the margin may have decreased somewhat by now. I suppose I should do the maths again at some point.

 

 

Edited by rusty69
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I have no idea how good/expensive etc this is but noticed it the other day and meant to find out exactly what it is  and how it works

https://m.facebook.com/story.php?story_fbid=pfbid02zZmqoLi5jHm3vNqn7yeha7uxUWzvXzqaaSYpXQ4Kym17mNW8HAtKKde3DFarJhZil&id=100063489644980

 

For those non FBers all the post says from CP Engineering is-

 

Recent solar optimization module programmed and fitted. Make use of your solar energy whilst still connected to shore power and reduce your electricity bill!

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2 hours ago, blackrose said:

I have a gas water heater but I can't imagine using gas to heat water is going to be any cheaper than electricity, even when the electricity cost goes up. 

 

The point for me is that if I'm going to switch over to shore power every time I want to run a high power mains appliance like the immersion or washing machine, that means the solar panels/batteries/inverter would only be used for things like AC table lamps (with energy efficient bulbs), mains TV, and a few other things + the the 12v system, all of which amounts to minimal use of electricity anyway when compared to the power demands of the immersion & washing machine. So I'm struggling to see the point of the panels. It might take decades to recoup the installation costs.

 

The rationale behind the on-demand water heater is not whether it's cheaper over a long running time, but for how long it is used, thereby reducing costs, by only using when needed. An emersion heater heats water you may not even use. 

 

For the washing machine, although I have an inverter, I would probably use the generator for that job. And it's possible to devise a system to fill the washer with already warmed water, saving the use of the heater element. If needs be, just bung in a couple of kettles of boiled water, then throw in the clothes and continue filling. On a day like today, the weather is crap, and I doubt the sun is of that much use. 

 

 

Edited by Higgs
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2 hours ago, PaulJ said:

I have no idea how good/expensive etc this is but noticed it the other day and meant to find out exactly what it is  and how it works

https://m.facebook.com/story.php?story_fbid=pfbid02zZmqoLi5jHm3vNqn7yeha7uxUWzvXzqaaSYpXQ4Kym17mNW8HAtKKde3DFarJhZil&id=100063489644980

 

For those non FBers all the post says from CP Engineering is-

 

Recent solar optimization module programmed and fitted. Make use of your solar energy whilst still connected to shore power and reduce your electricity bill!

Just spoken to CP engineering about this and it seems from his description how it works to be a sensible piece of kit for those with shore power and solar. It's certainly given me food for thought on a modification to my systems.

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20 minutes ago, Loddon said:

Just spoken to CP engineering about this and it seems from his description how it works to be a sensible piece of kit for those with shore power and solar. It's certainly given me food for thought on a modification to my systems.

Excellent. 

I dont have solar at present-given Im on a shoreline and away alot its just not worth it for me at present. But this may just change my mind.

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7 hours ago, Higgs said:

 

The rationale behind the on-demand water heater is not whether it's cheaper over a long running time, but for how long it is used, thereby reducing costs, by only using when needed. An emersion heater heats water you may not even use. 

 

For the washing machine, although I have an inverter, I would probably use the generator for that job. And it's possible to devise a system to fill the washer with already warmed water, saving the use of the heater element. If needs be, just bung in a couple of kettles of boiled water, then throw in the clothes and continue filling. On a day like today, the weather is crap, and I doubt the sun is of that much use. 

 

 

 

Yes I see your point about the gas water heater, except that pesky continuous pilot light wastes quite a lot of gas unless you light it every time and remember to turn it off afterwards. 

 

My immersion is on a timer for an hour twice a day so I'm not wasting energy heating water I'm not using.

 

Yes it's easy enough to fool the washing machine but again those kettles of hot water are just being heated by gas. My machine won't start from my semi sine wave inverter, but I'm sure it's more expensive to run a generator to run the machine compared to shore power even with the electricity price increase.

 

It all just seems to be introducing a load of hassle without any real benefit. 

5 hours ago, PaulJ said:

Excellent. 

I dont have solar at present-given Im on a shoreline and away alot its just not worth it for me at present. But this may just change my mind.

 

Yes thanks for that. Perhaps it will change my mind too... 

Edited by blackrose
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1 hour ago, blackrose said:

Yes I see your point about the gas water heater, except that pesky continuous pilot light wastes quite a lot of gas unless you light it every time and remember to turn it off afterwards. 

Don't instantaneous water heaters come with electronic ignition these days?

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1 hour ago, David Mack said:

Don't instantaneous water heaters come with electronic ignition these days?

 

Most of the basic ones you find on boats have a gas pilot light that need to be lit and switched off -or alternatively left on all day wasting gas. I'm sure there are more expensive and sophisticated models, but I guess it depends on what's been installed. 

Edited by blackrose
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9 hours ago, blackrose said:

 

Most of the basic ones you find on boats have a gas pilot light that need to be lit and switched off -or alternatively left on all day wasting gas. I'm sure there are more expensive and sophisticated models, but I guess it depends on what's been installed. 

 

Even my old Paloma has push-button to light the pilot. It's no hassle to turn it off and on. 

 

12 hours ago, blackrose said:

 

Yes I see your point about the gas water heater, except that pesky continuous pilot light wastes quite a lot of gas unless you light it every time and remember to turn it off afterwards. 

 

My immersion is on a timer for an hour twice a day so I'm not wasting energy heating water I'm not using.

 

Yes it's easy enough to fool the washing machine but again those kettles of hot water are just being heated by gas. My machine won't start from my semi sine wave inverter, but I'm sure it's more expensive to run a generator to run the machine compared to shore power even with the electricity price increase.

 

It all just seems to be introducing a load of hassle without any real benefit. 

 

Yes thanks for that. Perhaps it will change my mind too... 

 

 

I don't fully understand the logic behind having the emersion on for two hours a day, as apposed to the on-demand option. Do you actually get through two emersion/calorifier  loads of hot water a day? And your generator probably isn't suitable for some uses, because of the wave output. I spend my time without shoreline mains, and when a washing machine needs to be used, it will always cost in power. Either I use the machine without the heater on or I boil a few kettles of water and throw those in first. That's an unavoidable use of the inverter or generator and gas. I would prefer the generator, to whacking the batteries, which then would need charging.  

 

It's just one of those things, when you're not hooked up to the mains, you have to tailor your energy needs to what is available. If you want to save money, it generally will require some adjustments. Some people collect wood, but I'm not that keen on doing that, and I can't avoid spending some £600 over the winter, for smokeless; that's six month's non-stop heating. I could save that £600, but...

 

 

 

 

Edited by Higgs
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12 hours ago, Higgs said:

 

Even my old Paloma has push-button to light the pilot. It's no hassle to turn it off and on. 

 

Yes my Morco has push button ignition to light the pilot light, but I don't think that's what David meant by electronic ignition. 

 

I didn't say that it was a hassle to turn it on and off, it's just that if you don't remember to turn it off it wastes gas. 

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13 hours ago, Higgs said:

 

I don't fully understand the logic behind having the emersion on for two hours a day, as apposed to the on-demand option. Do you actually get through two emersion/calorifier  loads of hot water a day? And your generator probably isn't suitable for some uses, because of the wave output. I spend my time without shoreline mains, and when a washing machine needs to be used, it will always cost in power. Either I use the machine without the heater on or I boil a few kettles of water and throw those in first. That's an unavoidable use of the inverter or generator and gas. I would prefer the generator, to whacking the batteries, which then would need charging.  

 

It's just one of those things, when you're not hooked up to the mains, you have to tailor your energy needs to what is available. If you want to save money, it generally will require some adjustments. Some people collect wood, but I'm not that keen on doing that, and I can't avoid spending some £600 over the winter, for smokeless; that's six month's non-stop heating. I could save that £600, but...

 

 

No I don't get through 2 full calorifiers of hot water every day.. Have you never used a timer in conjunction with an immersion heater? I can't believe I'm having to explain this but an immersion heater doesn't need to heat a calorifier from cold and the thermostat means it switches off when it reaches the set temp. Having it come on for an hour in the morning and again in the afternoon means the water is hot rather than just warm anytime I use it. 

 

I have the on demand gas water heater option if I want, but in my experience of using both the gas is much more expensive. So the only time I use the gas water heater is if I'm away from the shore power and have been moored somewhere for a few days and haven't run the engine. 

 

My generator can run anything on my boat. It's a Honda and the sinewave is fine. I'm not sure why you assumed otherwise?

 

You make a lot of assumptions about people you don't know. I spent 3 years CCing so I don't really need a lecture about how to tailor one's energy demands when off grid. This thread is about being on shore power while using solar panels. 

 

Sorry but I've been living on boats for over 20 years and you're talking to me like I've just bought my first boat. 

Edited by blackrose
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43 minutes ago, blackrose said:

 

No I don't get through 2 full calorifiers of hot water every day.. Have you never used a timer in conjunction with an immersion heater? I can't believe I'm having to explain this but an immersion heater doesn't need to heat a calorifier from cold and the thermostat means it switches off when it reaches the set temp. Having it come on for an hour in the morning and again in the afternoon means the water is hot rather than just warm anytime I use it. 

 

I have the on demand gas water heater option if I want, but in my experience of using both the gas is much more expensive. So the only time I use the gas water heater is if I'm away from the shore power and have been moored somewhere for a few days and haven't run the engine. 

 

My generator can run anything on my boat. It's a Honda and the sinewave is fine. I'm not sure why you assumed otherwise?

 

You make a lot of assumptions about people you don't know. I spent 3 years CCing so I don't really need a lecture about how to tailor one's energy demands when off grid. This thread is about being on shore power while using solar panels. 

 

Sorry but I've been living on boats for over 20 years and you're talking to me like I've just bought my first boat. 

 

I only heat water I need, unless the engine has been running, in which case, water is heated as a bonus.

 

 

Edited by Higgs
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I think it will be a very long time before panels and MPPTs would pay for themselves, but it might be possible to give a very, very approximate idea of the cost saving over a year. 

My 1400watts of panels have recorded generating about 640kW of electricity in the almost 12 months since I finished the setup. 

I must add that I have a switch that disables the MPPTs when the battery SoC reaches its target value (currently set at 80% SoC), and that means during the summer they could have generated more, but on many days they were switched off some time in the early afternoon because by then the water was hot and the batteries were as full as I wanted them to be.  

So that 650 Kw could have become 900 Kw or more, if I hadnt had them switched off for many hours on many summer days. 

But in terms of the electricity I've actually used, its been 640kW, which on hookup would cost me about £130. 

The panels, mounts and MPPTs cost about £600 and I fitted them myself (with some expert guidance from our resident gurus), so at the current rate it would take well over 4-5 years to pay for themselves, if was on hookup. 

 

But as I'm CCing, and only cruising about once a week, the big saving for me has been in diesel. Without the panels I'd have had to run my engine purely for electricity on 6 days of each week, and I'd be using about a litre of diesel each day to do that (and on some days more). 

If I was to price diesel at say £1.50 per litre since the start of April, the panels have saved me using diesel on about 100 days, so that's saved £150 so far this year.  

Over a full year I would imagine the panels will save me about £230, so they'll have paid for themselves in another two years. 

 

(That's not including the cost of an engine service every 200 hours, which could be from £30 if DIY up to £150 if done by a professional. Plus any costs/reduced boat value that might arise from the extra wear and tear on the engine itself from the increased running hours) 

 

 

 

Edited by Tony1
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1 hour ago, Tony1 said:

But in terms of the electricity I've actually used, its been 640kW, which on hookup would cost me about £130. 

Maybe last year. A going rate for domestic is now somewhere about 55p so that's £352.

 

 

1 hour ago, Tony1 said:

The panels, mounts and MPPTs cost about £600 and I fitted them myself (with some expert guidance from our resident gurus), so at the current rate it would take well over 4-5 years to pay for themselves, if was on hookup. 

More like 2 years

 

Just as an example the payback time on my home system has gone from 11years down to 6years due to the rise in electricity prices.

Edited by Loddon
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