Next Day Solar is committed to educating the younger generation, whilst (as our day to day) helping our customers install solar panels, battery systems and energy saving devices, and so we provide a short summary of our recent work in an educational setting.
If you are a customer of next day solar, you have helped to ensure we can continue to carry out these days. If you are considering an installation, you will be helping us carry out this vital work in the future.
We also provide a link to our planning, if you are looking to run an ‘eco day’ in an educational setting, with examples of activities you can do with groups.
https://docs.google.com/document/d/1WQgVZhHTNjUgGYHxUUJ_b2pLx3QKY9UT1eTlD7Y4Fsk/edit?usp=sharing
We arranged our eco day into 5 different areas, and the children moved through each of the stations. We were able to see 6 year groups on this day.
Wind Power – Construction of wind turbines, and meccano models, and demo of our giant turbine.
Solar Power – Solar games, solar models and so much more
Hydro Generation – We built our own hydro system, which helped kids understand how water from higher points can be run over a turbine during the night to generate energy when the sun isn’t shining, and using solar in the day to pump the water back up to a higher point.
Bio Diversity – Talking about where the bugs have gone, and building bug homes to re-store homes for bugs who have lost their natural habitat.
Food Growth – Talking about the benefits of home grown, saving carbon, food miles etc and planting food to take home.
A few photo’s below to help illustrate the day we did.
Special thanks to the teams behind the scene's helping us prepare for these events.
And the prototypes !
Thank you
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What happens when the grid has a shortfall of energy?
How can home energy systems, contribute intelligently to grid in a more dynamic way?
]]>What happens when the grid has a shortfall of energy?
How can home energy systems, contribute intelligently to grid in a more dynamic way?
Welcome to the future of energy in the UK, dynamic pricing, where prices fluctuate every 30 minutes, the more energy you can store, or give back, the less your likely to pay when it comes to the monthly bill… interested ?
In this article, we will address the developments coming, and already live in some parts of Europe allowing consumers to work alongside the grid in supporting a carbon neutral future.
Brief Timeline
The graph illustrates the problem with this, as when the homeowner is unlikely to be at home, energy generation is at its peak, and when the homeowner needs the energy its being drawn from the grid, due to low generation. 4-7pm is the dirtiest hours for the grid, when the most fossil fuels are burnt.
You can see the during peak generation in blue is stored in the battery to be used later in the day, excellent.
How can the free market respond, in a way that can help the consumers achieve a lower price for their energy?
If the grid is able to push excess energy to consumers when it has too much of it and ask customers not to use or share energy when it doesn’t have enough of it, it would be immensely beneficial. If the system is efficient, at dealing with peak demands at busy moments, fewer, new power stations will be required, which further keeps costs down for energy customers, as our hunger for power hungry appliances continues.
So how did he achieve this?
The software for this application is freely available on github here : https://github.com/tfranssen/dynamic-ess
And a number of scenario’s are presented where you’d expect a system to respond:
I am excited about the benefits this can bring to all as part of the green energy transition and will keep our readers updated about its progress.
I understand Victron’s own Dynamic ESS system will be looking at the home’s energy consumption within the past 28 days, weather tables, and pricing in order to as efficiently as possible ‘place a bet’ on how much and when to charge batteries.
Existing Octopus energy customers can apply to be put onto the ‘Agile Octopus’ here https://octopus.energy/agile/
We will keep our readers updated on these latest developments.
]]>In addition to providing aid to those affected by the conflict in Ukraine, this opportunity has allowed us to conduct testing on our products in a real-world scenario. While our initial attempts to power a large heating system were not successful, we were able to successfully power a combi-boiler or standalone boiler using our devices. This testing has provided us with valuable insights on how our products perform in the event of a grid failure and will help us improve and refine our technology.
We arranged transportation to a city where we have strong connections through one of our team members and distributed the equipment to individuals who had lost someone on the front lines.
Our assistance has provided ongoing support to 25 families by enabling them to continue their daily lives even when their main power is disconnected. It also allows them to do so in a completely free and sustainable manner.
See a video from Ukraine of our Adventurer power box being used to power their gas boiler.
Adventurer powers gas boiler
Uploaded by Next Day Solar on 2022-12-22.
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With astronomical increase on bills effective from April 2022, with the increase of the energy price cap, getting the most out of your solar system is critical.
Solar PV energy generation often does not match the energy demand of a typical home during a typical day. A ‘Due South’ system’s energy generation profile will look something like the below on a nice bright day, with a slow and steady gain in power, peaking in the middle of the day, and then a slow and gradual decline. This graph relates to a period in March. You’d see a more gradual and wider bell curve during peak summer months, with longer, brighter days.
Moments of cloud cover, shading or rain will cause the power generation throughout the day to be more varied, the graph below shows a dip at 13:45pm where the system loses a considerable amount of power and then improves, before tailing off for the day.
Below is a typical home’s energy demand profile over a given day. The average energy consumption in ‘standby’ i.e when basic things such as fridges/freezers/lights/heating functions is around 250watts. In the morning, kettles and other equipment cause a spike in demand, followed by a ‘wash cycle’. As we move through the day, a dishwasher may cycle, and for dinner the oven may be used, with an increased load as more lights are put on during the evening/darker moments.
Let's now look at this with the overlay of energy generation of a 1.6kWp system.
As you can see, there are large parts of the day where the home’s energy demands outstrips (greater than) supply. This is represented by the blue shaded area. Equally, areas shaded in red, with a white backdrop show times where solar pv generation is greater than the home’s demand for energy.
In a grid tied system, this energy would normally be fed back to the grid, and you may receive a small credit for this surplus.
There are a number of solutions to better manage the energy you make from your Solar PV system, to ensure you are either storing it for use when you need it, through the use of a battery, or diverting it to your hot water tank immersion heater, in order to heat your water.
We will take a look at both scenarios here, and look at the pro’s and con’s of both, and then investigate further how to ensure the system is operating efficiently.
The battery reached its lowest point of (SOC 6%) at 10:20am, and then the solar system production began to outstrip demand, and the battery quickly regained a charge to 100% at 14:38pm.
The second/alternative option we want to explore is fitting a device which monitors how much energy you are exporting back to the grid, and ‘sends’ that energy to an electrical coil in your hot water tank, and in effect diverts any excess electricity you have, to ensure it's used in your home or workplace.
(We are in no way affiliated to this product) it just works…
The Solariboost has a CT (current transformer) clamp which gets placed around your positive cable that feeds your home’s electricity. This is linked to a small transmitter, which is sending information to the main ‘iboost’ which is directly connected to your immersion heater, controlling how much power should be used.
The advantage here is that you are then able to use all that extra energy you are using to heat your hot water, and avoid burning gas to do just that. The iboost is relatively inexpensive, and of course there are other models that perform a similar function, but we found with the simple display, it’s a useful bit of kit.
In this particular installation, the iboost was fitted with the rest of the solar equipment in the loft nearby a hot water tank, but provided there is a live supply suitable rated up to 3kw, it can be placed anywhere in proximity to the tank.
There are a number of drawbacks to this system which I want to explore in further detail, as I do feel they open up the options for looking at more intelligent systems, for better managing one’s extra energy output.
There are typically 2 main ways of heating hot water in a home using natural gas which we need to explore as a pretext.
The solar Iboost is only suitable for systems with a hot water tank, i.e not a combi boiler setup.
This takes some fiddling, too hot, and you risk overheating the water in the tank which comes with its own dangers and concerns, too low, and you risk wasting the excess energy you have generated. I feel both the iboost and immersion heater probes themselves could have improvements to better match and set up the temperature of the coil.
2) The second drawback that I found when playing with the system relates in a similar way to how solar energy production and demand are often at different times of the day. Typically households may use hot water in the morning and the evening when solar production is at its lowest point. During the middle of the day, hot water demand is likely to be at its lowest point, many of today’s household consumers such as washing machines and dishwashers have their own internal heating elements to deal with hot water demand.
What this therefore means if that if you are relying on solar energy to heat an immersion heater probe, to provide you with hot water, it's often at the wrong times, and you’d find in the morning your water wasn’t warm enough, and whilst excess solar PV energy in the day would heat the tank up sufficiently, for earlier showers, later in the evening the temperature of the tank would start to drop and you’d then be reliant on the gas again to heat your water. The graph below illustrates just this, the red area’s show demand when excess energy to heat the hot water is unlikely to be present.
3) A third and final drawback or concern relates to control. Most homes will have a method for controlling when the ‘gas boiler’ is set to heat hot water. This may be through an intelligent system such as ‘heat miser’ or a more basic thermostatic control, with a few set points during the day.
The problem is these systems are not intelligent. In an ideal world, if solar production is likely to outstrip the demand of the home, you’d like to keep your hot water off for as much as possible during the day, to ensure the set point of the hot water tank is low, and therefore the excess solar PV is used to heat the water up. However, if in doing this, you turn the system off, and then on a cloudy day, or high usage day of energy at home, you don’t send much energy to the immersion coil, you are left with cold water. As the systems are unable to communicate often, you are left trying to balance having the hot water on enough to ensure when it comes to shower time, you are not left cold, but also ‘off enough’ to ensure you are utilizing the excess PV energy. Coupled with setting the right temp on the thermostat it's an incredibly tricky endeavor.
Having tested initially, we did however find the following results in a single month period.
kWh |
PV Generation |
Grid Export |
Hot Water Consumption |
Self Consumption |
Export |
Hot Water |
Self Consumption |
March 2022 |
108.53 |
24 |
5.65 |
78.88 |
22.11% |
5.21% |
72.68% |
Having seen relatively poor results in March, I have tweaked the immersion heater temperature control upwards, to ensure the system is pushing back to the grid less, and heating the hot water more. I will in due course report on subsequent results.
Battery storage solutions are a fantastic way of reducing your dependence on the grid, and storing excess solar energy for use when you need it most. If you cannot quite afford the investment, and provided you have a hot water tank, an iboost or similar device will help you retain some of that excess energy, but as we address in detail, its a real balancing act, and it may drive you quite simply round the bend trying to eek out the most of your watts generated. With either solution you’ll be reducing your grid dependence, and using a cleaner source of energy production, leading to a cleaner greener future.
Thank you
Here at Next Day Solar, we really believe that solar energy is going to play a big part in shifting the world over the next 30-50 years to a more self-sustaining way of living. Many things that we do such as using hot water, transporting ourselves around, operating machinery, all require electricity, and if we can make that from the sun, rather than through burning something, surely, we will be better off.
In this short article we will explore the advantages and disadvantages of solar, as well as some interesting and un-expected applications.
So there you have it, our top 5 ad's and dis ad's of solar energy. Whatever you decide to do, you'll be making a great step forward for the planet, and if you have any questions, don't hesitate to reach out to us.
Thank you
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One of our ambitions at Next Day Solar, was to share our knowledge with younger generations, after all they will be the one's that will be cleaning up the mess we have made.
One of the ways we can all live more sustainably, is generating and using our own power, reducing our reliance on the grid, which, in-turn will reduce the amount of fossil fuels being burnt, and the number of power plants being created.
If homes in 10 years time generate their own energy, think of how much copper would be saved when new homes are built, reducing any requirement to be connected to the grid !
We've started visiting a number of schools and clubs, and if you are keen for us to visit your nursery/school/college or event please get in touch.
We began assuming those I was talking to new absolutely nothing about electricity, let alone solar energy.
For younger children I usually start with a wind turbine in my hand, which is powered using a solar panel, using a handy torch I am able to demonstrate 'magic' by making the wind turbine spin with only the power of light. This is a good way to dive into energy and electricity. A few easy questions such as (what is making the propellor spin) can be helpful.
From here, we start to talk about electricity, what do we use when we wake up in the morning ? what makes the lights shine, what else does electricity power.
Now we've introduced the concept of energy, I start to discuss how electricity gets to the house. I use a large gauge DC cable, with red and black covers to illustrate the principle.
From here the discussion moves to how energy is made, most children will talk about static/friction/rubbing from things like jumping on a trampoline, or rubbing a balloon. I like to talk about power stations, nuclear, wind, hydro as places that energy is made. We then move on and talk about the dirtier means of making electricity such as coal fired plants.
I have created a small dynamo and light setup, and at this point I generate my own electricity, to try to demonstrate the notion that energy doesn't have to be made in all of these distant places.
To make the session fun, each child is given the opportunity of having a go generating their own electricity, on the winder which keeps everyone very engaged.
For younger children, I then bring along a set of solar powered toys, and let the children play with these. One of the best games is letting the cars race against each other. One of the best ways to educate the children about the suns energy, is to let the children cover the panels with their hands, and then un-cover and watch the toys come to life.
Typically, I finish the session talking about where solar panels could fit on a home, and get the children to draw a house with solar panels on top of it.
We are able to tailor our experiential classes for all ages.
Here we demonstrate how solar energy can be transformed to power lights, and then introduce a battery/inverter system to demonstrate how energy can be stored for use when the sun isn't shining.
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Next Day Solar Visit Viridian Solar in Cambridge, to find out about their Clear Line System that installs directly onto the rafters of a roof.
We were invited to Visit Viridian Solar UK who are the UK's only manufacturer of integrated solar panels. In less than 30 seconds, Viridian pride themselves on a system that avoids the need for roof tiles beneath the panel, so the panel effectively becomes the roof tile.. smart, and you use less materials in completing a roof. The edging will always be a tile finish, but its a much smarter way of applying solar panels to a roof, and comes with a stack of benefits.
The 'Clearline' solution is predominantly used on new builds across Europe and USA, however its more and more being used on renovation projects too, where an existing roof structure and tile is in place. Old tiles are removed, membranes and rafters are checked, and the new solution is put in-place, whilst making all the necessary connections to a battery/inverter system.
Viridian specialise in a select number of panel sizes. All panels are +270watts, with an open circuit voltage of 40 in ideal conditions. There are currently 5 models in the range, going up to 330watts. Small differences are present, white/black backing and mono/poly options are available.
We set about installing our first panel, as you'll see a flashing is included with the Viridian kit, this gets fixed down to the bottom row of tiles, ready to flow into a gutter.
A few hours later, and some learning under our belt, we had managed to install all 4 panels into a simple grid configuration.
After seeing the system installed, and the adjacent hose pipes opposite, that are used to test the system regularly, I'd have great confidence putting these on my roof. They protrude ever so slightly, 63mm to be exact, from the rafters they are fixed onto, which in my view makes them look like they are not sinking into the roof and looks super smart.
Great care has been taken with all the flashings design to ensure there is no chance of any water entering your property below. Was really impressed with our day at Viridian and would highly recommend them for anyone looking for a flush fitting solar panel system on their roof.
Positives
They are SUPER strong, we don't advise to stand or do anything of the sort on them, that would be dangerous (on a roof) and bad play, but its good to know they can take the strain if a giant bird decided to make land on your roof patch, or a pair of solar enthusiasts.
- No ugly brackets or bars visible
- Reduced wind noise from inside the roof, and no concern of debris/rodents or other getting trapped beneath the panels
- reduced dynamic load on roof (less ability for wind to get underneath) which is a big issue with conventional bracket systems
- Easy install, all the brackets, fixings and flashings come in the pack, so no requirement for your fitter to go hunting around for parts.
- Well priced and lovely team !
- Velux window's can be integrated.
Considerations (as that's what Con's stands for isn't it ) !
- You'll need to remove some tile if you are looking to retrofit, which may increase the costs of your roofer slightly, but you'll have a much better looking job and it will be well worth it.
- The panel size is quite restrictive and currently there are no corner or smaller panels available for those trickier parts of the roof.
- There is a velux option which is great, but its currently only available in a 9 config rations which means you'll need a well sized roof to even start to consider this, although plans are a foot for improved configurations i hear.
If your interested to find out how the system is installed, here is a short 5 minute video for you to watch :
]]>Project Summary: I planned to instal 2 x solar panels on the roof of the tree house, connected to a simple battery system and lights. The children would be able to activate the lights, and learn about how the solar panels were powering the lights. Using a smart solar charge controller, the system would detect daylight, and turn the lights off, and dusk to activate the lights automatically.
Start:
To start with I sized up the roof, and purchased 2 x Victron 40w 12V Panels. These have a PMAX of 2.1Amps, so in series I could expect +24V and 1-2 amps dependant on conditions. If wired in parallel, a maximum of 4.2amps at 12v.
The smaller sized Victron panels do not come with MC4 connections, I had originally understood that this meant no cables came with the unit, and I'd simply need to buy solar cables with MC4 ends to plug directly into the panel. This wasn't the case, the unit comes without any easily pluggable connectors, so it required me to remove the waterproof panel and make a physical connection with my 4mm solar cable.
*Note on any small panels check what connections they come with before buying the cables, which you may not need.
Here you can see the MC4 cable I purchased were not suitable.
I used a simple stripper tool to remove the double walled cable protection. This reveals the 4mm solar cable, which I was then able to insert into the gland. Note always remember to put the screw and cover onto the cable before preparing to fix, otherwise you'll have to start all over again.
A suitable crimping tool and end would of worked here, but I was also able to insert the cable and with a pair of pliers, just squeeze the ends to keep the cable safely in place.
I'd successfully wired up my first panel. I was going to run the panels in series, so the negative out from the first panel, was going to link to the second panels positive in. This mean I needed 3 lengths of cable between the panels and the solar charge controller. Wiring in series does help save cables and equipment as you don't need 2 sets of positive and negative strings in small setups like this. Its important when wiring in this way to ensure the solar controllers maximum input voltage isn't exceeded.
Educating my daughter about PV panels was important, so I made sure she fixed the brackets good and proper. For this application I used a simple Z bracket, which fixes to the panel using a nut and bolt, and then has 2 pre-drilled holes to fix to a variety of surfaces. I was going to use small timber screws to apply to the roof of the treehouse, so as to ensure I didn't perforate through the slats and cause a safety hazard.
Both panels, were wired, and I then set about fixing them to the roof, with a little help from my friend. Solar panels would always want to be mounted south facing where ever possible, to get the most energy from the sun during the afternoon at its peak point, however in this setup I had a south and north facing slope, so I decided to mount on both faces. Having both faces ensured I will capture morning and afternoon sun, which would be better than just having a single panel on the roof.
As part of the installation, I drilled holes into the timber roof, and fitted a waterproof casing, which would house the solar charge controller and all connections to ensure the setup was fully waterproofed and safe, especially with children in proximity.
Having successfully wired the panels, and fixed them to the roof it was time for testing, to before connecting my battery and solar charge controller. I planned to wire up a set of 12v lights that I'd found these seemed fun, and something I thought the kids would enjoy playing with.
The lights arrived, they were a series of 20 x 3V LED globes. The power rating on each globe was 0.064w, which is 1.28w in total for the 20.
Using the simple calculation Watts/Volts = Current, I was anticipating a current draw of 0.4amps. As you increase the voltage, the current is reduced (which is why larger scale setups always run on high voltages, to reduce the size and specification of all components involved, so at 12v my expected current would be around 0.1amps.
I connected the lights, and set the solar charge controller to automatic, the panels sensed no voltage due to the darkness and the lights were activated.
The current registered at -0.2A, which was higher than my calculations but still well within a suitable tolerance. This was an incredibly low power setup.
I set about stringing my lights up, and whilst the globes at (3V) each were not the brightest, they did the job of illuminating the area well.
I made some calculations based on the energy consumption and solar panel yields I expected. This was based on using a 24ah Lithium Ion battery, which I did intend to swap in the future for a lead based or AGM battery, as the Lithium battery was an over compensation for this rather basic setup.
My calculations showed below that I was able to add even more lights to the setup, and still have more energy each day, than was needed at night to power the solar lights.
Power Consumption | Winter | Summer |
Darkness | 5pm | 9pm |
Daylight | 7am | 6am |
Hours of Darkness | 14 Hours | 9 Hours |
Hours of Daylight | 10 Hours | 15 Hours |
Energy Consumed Per Hour | 0.3 Amps (12v) | 0.3 Amps (12v) |
Total Energy Consumed Each Night (amps) | 4.2 | 2.7 |
Nights of Power with a full battery without solar | 5 Nights | 9 Nights |
Energy Generation | Winter | Summer |
1 x 12v 40W Panel - PMAX | 1amp | 2amps |
Daylight Generation in amps | 8 amps | 24 amps |
Watts | 96 | 288 |
Consumption Each Night (W) | 50 | 32 |
Daily Power Surplus (W) | 46 | 256 |
Light Strings that could be added | 1 | 7 |
That was the end of my first solar powered tree house adventure. My system was ready in the future to add further power demands, such as a small inverter, to power any hand tools or gardening equipment needed in the local area.
If you have any questions about this setup, or would like some advice on your own setup you can reach out to us here
When doing this setup, I found it handy to have my all-in-1 solar system with me, it provided light, as well as a 300w power source, for when I was heat shrinking the cables. Quite a handy tool to have around the garden.
Happy Solaring !
]]>The setup was rather basic, 2 x 100amh lead leisure batteries, designed to power a hubbard fridge system, that on peak load drew 70amps at 12v, and once the fridge had reached temperature, load draw was around 55amps. This meant the fridge would last between 3-4 hours on a good day. It was then helped by a 100w flexible panel attached to the roof contributing another 20-30amps of power per day. Nice little setup.
We started getting into problems during the summer, when after a hot day, the van would run out of battery power to run the fridges, and the batteries would come back totally depleted. We'd put the batteries on charge, as we would every night but they wouldn't take a charge. Only after resorting to a specialist slow charge system, or letting the solar cell drip charge the batteries the next day would the battery take charge again. This resulted in many days when the van would be off the road for safety reasons, no fridge, no van.
After exploring battery technology further, it was clear these batteries were not suitable, and the setup they'd been placed into wasn't fit for purpose. Lead batteries should only be depleted to approx 50% of their capacity, this is 'depth of dis-charge' where as we were depleting them to 100%. Eventually we'd totally ruined the battery, and the power the battery was able to provide diminished quickly.
After getting quite up-set with the installation, we were provided 2 new lithium batteries. Each 100amh, costing around £800 per 12v battery. These would give a much better depth of dis-charge, safely, resulting in a similar amount of cooling time from the fridge, but in a way that preserved the life of the battery.
A number of changes were made to the setup to ensure we didn't do the same damage to these batteries as we did to the first set of lead batteries.
1) The first change was the battery charger.
Lithium chargers work differently to standard lead/agm battery chargers in a number of ways. Lithium batteries do not like being over charged, so the charger limits the amount of current to a set level, until the battery reaches a specified (often customisable) voltage, and then the charger switches to power supply mode only. You will often notice a sharp rise in voltage toward the end of a charge cycle as the current drops off quickly.
Lead chargers work in a very different way. They often have 3 phases of charge, bulk, absorption and finally float. After the battery is 80% charged, the charger moves to a different phase as the charge current is reduced.
What I have learnt is that most lithium chargers have an algorithm that will enhance the lifespan and performance of the battery. Leaving a lead acid battery charger connected to a lithium battery is therefore not best practise.
We installed a marine battery charger (CTEK PRO25S 12V 25A Smart Charger) charging at 25amps which would feed the batteries over an 8 hour cycle, whilst the van wasn't in use at night. This was a replacement for the CTEK MXS25 which is designed for lead batteries only.
2) The next addition to our setup was a battery protect system. We opted for a Victron system, with a smart interface. As the unit was installed within a sealed area, this allowed for remote monitoring and adjustment of the system.
We installed the Smart Battery Protect to ensure that the fridge system would shut down, when the batteries got to a point of depletion that was safe. Without this automatic shut down system, the fridge would deplete the battery completely, we would see a reduction in voltage within the cells, and again in the long term the life of the battery would be reduced significantly. The BMS we opted for was the Victron Smart BatteryProtect 12/24V-100A, this was more than sufficient to handle the peak 70amp load. Unlike Victron's battery management system, we connected the positive loads through the setup, and through the bluetooth application informed the system that we were running a lithium setup. A very small number of settings allow you to configure the what is essentially a large relay to suit your needs with alarm options to suit.
We've managed to convert the first of our vans over, and its working incredibly well. We are now in the process of upgrading our 100w panel, to a much larger panel, which will increase our current input into the battery from 4amps per hour at 12v to around 10amps per hour, in good weather, which I look forward to covering in a future post.
I hope we can be of help to you with your own solar and energy challenges. Feel free to write to us as hello@nextdaysolar.co.uk with your questions.
Thank you
]]>I'd often plug in my screen, so really I wanted to know could I power a computer and screen at the same time and what would I need to do it.
I started off with a 100w solar panel, in strong sunlight it would generate around 4amps of current, and around 18volts of power. I decided to opt for a lithium battery, 24amh, as my calculations suggested that this would give me enough power to last through a full day in the office.
My calculations were as follows
Consumption :
- Laptop power adapter - 12v @ 3amps
- 24" LCD Screen - 14v @ 2.5amps
Total consumption - 5.5amps at 12v.
The really inefficient thing about all our modern technology is that they are all generally really low voltage, so most appliances take 240v then bring it back down to a save voltage of 12v, before powering a device. The solar setup I had, was taking 12v, convening it up to 240v through the use of an inverter, and then the transformer at the screen was converting this back down to 14v again. There are now more and more appliances that will run on a direct 12v supply, saving you all the valuable energy.
So I'd worked out my peak consumption was 5.5amps, that would drain my battery in around 4-5 hours, but once my laptop battery was full, my consumption would drop to only around 2.5amps, on just the screen, my battery would last for almost 10 hours, plenty of time to do my solar calcs !
And this is all before, you take the input from the sun, on a great day you'd get between 6-8 hours of energy generation, on average 2-3 amps per hour, so around 20amps of power, and I'd only be depleting the battery by around 5amps per day.
Connected up to my 12v battery, I've installed a Victron BMS system, which gives me all the right sort of data on how much charge I've got left, how many amps I'm using or putting into the battery, and what state the battery is in. It will also turn off my setup once the battery is almost depleted ensuring that I don't discharge the battery past a point its happy with. A key point with BMS systems is always to connect all negative loads through the BMS so it can give an accurate voltage of consumption or energy harvesting.
I ran all my connections through a basic buzz bar, to give me flexibility to interchange batteries and panels and chargers freely, although a direct connection would suffice.
I opted for a smart Victron charge controller, this helped me manage my flows as I could view all the content from my handheld device (phone/tablet). It also allows you to fine tune how battery is charged, with lots of additional settings and features inside the app.
From my BMS system and battery, I then had a direct connection to a 1000w inverter. This was far higher than my requirements which were only around 70-100w, but its one I had around the workshop, so was perfect to use, and allowed me to grow my setup in the future. This type of inverter is pure sine wave which allows for a smooth and clean power delivery.
I've been able to power my computer and screen throughout the summer with ease, off grid. Whilst I'm enjoying a weekend away from the office, I enjoy knowing that my battery and solar setup are getting ready for the week ahead.
If you have any questions on your own solar setup, feel free to reach out and I'll be sure to help in aiding you setup your own home/office solution.
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