How to Choose SOLAR Wisely and Avoid Costly Mistakes

so you've decided to go solar but you're not sure you're buying the right setup and you don't know if your installer will do a good job watch this video and i'll help you through it [Music] hi i'm gary welcome back to my channel gary does solar if you're new to solar i recommend you watch my previous video which will bring you up to speed with all the basics in less than 15 minutes if you're ready to go solar and you want to know how best to do that you've come to the right place as with any big purchase it makes total sense to get quotes from a number of solar installers decide on the one that you like best then negotiate them down towards the price of the cheapest quote but in the world of solar this approach alone is unlikely to work and that's because there are so many technical options it's inevitable each installer will quote a different solution with different brands making it hard if not impossible for you to compare like for like and if you're trusting those installers to provide you with the best solution how would you know wouldn't it be better if you knew enough about the technology so you could ask all the right questions or better still what if you were sufficiently well informed that you could lay out exactly what solution you wanted which would allow you to compare quotes like for like spend a little time with me in this video and i'll take you through what you need to know so that you can make the best decisions and not waste your money okay let's get started for most solar installations the majority of your investment will go into these three areas solar panels an inverter and a battery now some installations will not require a battery and it's also possible to have installations without any panels but in this video we'll cover all three and then you can decide for yourself what kind of installation works best for you now before we get too far down the road there are quite a few things that could prevent or make it difficult for you to have a solar installation we should check these out just now is your home suitable for solar let's start with property ownership if you already own your home then great but what if you rent or lease a property you'll need to get permission from the landlord first then depending on where you live you may also need planning permission from your local authority in the uk most solar installations do not require planning permission but if you have a flat roof you likely will check with your installer who will have the latest information for the area that you live in now let's consider the orientation of your home with respect to the path of the sun during the day if you live in the northern hemisphere ideally you'll have a south-facing roof that you can put panels on to as this roof will see most of the sun throughout the day and for those living in the southern hemisphere then ideally you'll need to have a north-facing roof in our example here in the northern hemisphere the roof is almost fully south-facing which is good enough in the morning the sun rises in the east and will be shining onto the panels very soon after sunrise then at midday the sun will be at its highest point in the sky shining directly onto your solar panels later in the day the panels will continue to capture sunlight as the sun starts to set in the west now don't worry if your home faces east and west this also works if you're able to put panels on both of those roofs your east roof will capture most of the sunlight as the sun rises at midday when the sun is at its highest point in the sky both roofs will be generating power then your west roof will capture the sun as it sets your next consideration is shading take a look at the roof or roofs that you'd like to put on solar panels at various times during the day is there any shading from trees or houses or even objects on the roof like chimneys or dormer windows a small amount of shading during part of the day is not too much of a problem but any prolonged shaded areas on the roof are unfortunately not suitable for solar now are there any windows chimneys or other objects on or within the roof that could limit the number of panels possible on that roof this is because solar panels are typically large in size nearly two meters by one meter each panel next check the condition of your roof is there any damage this will likely need to be repaired before solar panels are added the good news though is that these repairs can be carried out at the same time as your solar installation a scaffolding will need to be erected for that anyway now solar panels are quite heavy weighing in at around 20 kilograms each and so the installer will want to check that your roof structure is strong enough to support the array size you'd like most properties built in the last 20 years or so should be fine but your installer will advise for your situation you'll need space inside or potentially outside your home to house the various electrical components required here are some examples of solar installations some are in the garage others are in the loft space some are even installed outside on an outer wall okay hopefully you managed to get through all that and your home is indeed suitable for solar great stuff let's get back to the three main items of equipment you will need then starting with the solar panels themselves there are two aspects to consider here first there is the size of the array required which will be determined by a number of factors including your annual electricity consumption and available roof space then there are the actual panels themselves which come in a variety of sizes and efficiencies and will be available from a number of brands we should start with the array sizing first you'll need to know your annual electricity consumption many energy companies will print this value onto your bill but if you can't find it just log into your account online and search for it now that you know how much electricity you use every year let's use an online tool to work out how much electricity you can generate with varying sizes of solar array no matter where you live in the world now this particular tool is not very user friendly but it is straightforward to use and i'll take you through it now the tool is provided by the european commission and it's called the photovoltaic geographical information system i'll put the link for it in the video description in essence this site maintains a database going back several years on just how much sun life hit the earth every hour at every location on the planet to use it head for the map section on the left hand side of the screen and zoom in to where you live we'll use a property near oxford in the uk as an example when you've found your house click on it and a pin will drop to mark it now turn your attention to the right side of the screen it looks complicated but we only need to adjust a few settings set the installed peak power to 4 kilowatts as a starting point set the roof mounting position to roof added building integrated and then set the slope to the slope or pitch of your own roof measured in degrees from horizontal finally set the azimuth which is a little more tricky the azimuth is the number of degrees your house orientation is away from south in the example here the house is almost south facing but offset to the west by around -12 degrees if your house is an east-west configuration you'll have two azimuth values so you'll need to run this utility twice run the west value first in this case around plus 62 degrees then run it again with the east value around minus 115 degrees with these values entered click on visualize results and you'll see a graph of how much electricity an array of four kilowatts will generate over the year broken down month by month there's no hard and fast rule for determining the best size of array but if you divide your annual electricity usage by 12 you'll get the monthly usage so you might want to consider an array that provides at least that much generation for eight or nine months of the year in reality and based on the experience of many solar enthusiasts the best size of solar array to have is actually the largest array that you can fit into your roof space panels are relatively inexpensive to other system components and so if you're already paying for the scaffolding you might as well add as many panels as you can okay let's look at the solar panels themselves there are quite a few companies to choose from when you're looking for solar panels and your criteria for selecting which panels to go with might end up being quite extensive including the brand there are plenty of solar manufacturers with products ranging from the budget end of the market right through to the premium end and then we can look at size solar panels from the different manufacturers come in a wide variety of shapes and sizes while most roofs will be straightforward like this one bear in mind that your installer will have to respect a margin of typically 200 to 400 millimeters at each edge by carefully selecting the right size panels you should be able to maximize the size of your array this is especially true for roofs with windows and other fittings like this one not too dissimilar from my own you might need to experiment with a few different panel sizes in order to get the most optimum solution and if your roof is such that it's almost impossible to fit many solar panels onto it then there's always solar tile technology from companies like tesla where each tile on the roof has its own mini solar panel quite clever really but the technology is still in its infancy onto efficiency then not all panels operate with the same efficiency and the more efficient a panel is the more power it will generate for the same surface area as your roof area is a fixed size the more efficient your panels are the greater the power generation will be for that fixed area here is a list of the more efficient panels on the market today we're looking at efficiencies nearing 23 and they're getting better all the time within a few years you can expect efficiencies of 30 and upwards appearance is another aspect on most panels you can easily see the solar cells but for a little more money you can get what are called black panels which are perhaps more aesthetic for your property bear in mind though that these panels might not be as efficient as their non-black equivalents some other things for you to consider then cost panel prices vary enormously with sun panels for example costing twice as much as other brands and it's certainly worth doing some cost analysis across brands particularly on size and efficiency to figure out the best solution for you warranty out of all the elements of your solar system solar panels are by far the least likely to fail for this reason you'll see warranties running into decades with a 25-year warranty being quite common be careful though as you may still be liable for engineering and scaffolding costs in the unlikely event of a failure in terms of performance panels have a long lifetime you should expect your panels to degrade only half a percent every year this means after 25 years they'll still be operating at 85 to 90 percent of their original capacity and finally availability with demand outstripping supply in most parts of the world despite all of your research you may be faced with selecting from the limited range of panels that your installer can readily get hold of okay so now we've covered solar panels let's move on to the next element of your solar setup the inverter these are what inverters look like and they're available from a number of manufacturers to understand what they do and why they're needed let's take a look at an example solar installation here we have a roof with six 400 watt panels on it we have the grid supply coming into the house which feeds all of the household appliances and we have cabling coming down from the roof ready to act as an alternative supply to the grid but we cannot simply connect these two supplies together as their incompatible forms of electricity the grid supply is what we call alternating current or ac but the electricity from the solar panels is direct current or dc to connect them together we'll first need to convert the dc to ac and this is done using an inverter there are different types of inverters so we'll start with the simplest kind called a string inverter with this kind of inverter the panels are connected together as a string on the roof and then into the inverter this makes for a very simple installation and is suitable for most homes but if there are any shading issues this will have an adverse effect on the whole string a slightly more advanced inverter solution comprises of a string inverter plus a small power optimizer unit fitted to each panel in the string these power optimizers communicate with the inverter via a dedicated communications link the advantage of this solution is that the power optimizers can continually monitor and report the power output of each panel if any shading occurs it will only reduce the power output of that particular panel so here we only drop to 1.8 kilowatts furthermore if a panel were to fail completely the power optimizer will work around it so the power will still be collected from all the other panels in the string so here we can still maintain 1.5 kilowatts instead of going to zero there is a third type of inverter solution where micro inverter units are fitted to each of the panels this means the conversion from dc to ac happens in the panel itself so there is no need for a string inverter unit inside the home these micro inverters also provide all of the same benefits as the power optimizers in the event of any shading or panel failure here's a quick summary then of the pros and cons of each type of inverter the string inverter is the most cost effective solution it has the simplest technology and so there's less to go wrong in a hard to reach place but individual panel shading or failure will affect all the other panels in the same string with the string inverter plus the power optimizers shading or failure of a panel won't affect other panels and it does allow remote monitoring of individual panels it is however a more expensive option and additional technology in a hard-to-reach place could be a costly fix should it fail and finally micro-inverters again shading or failure of a panel won't affect the other panels and like with power optimizers it allows remote monitoring of individual panels and there's no need for a large inverter unit inside the house it is however the most expensive option and just like with power optimizers this additional technology in a hard to reach place could be a costly fix should it ever fail before we leave the topic of the inverter then one other factor to consider is the size or power output of the inverter string inverters come in many different sizes and here are some of the available sizes from the solar edge inverter what's the best size to get then well it depends on a number of factors the first is the size of your solar array you certainly don't want to get an inverter that is larger than your solar array because that extra cost would be wasted it's okay and actually very practical to get an inverter that is smaller than your array firstly most of the time the solar array will not be producing anywhere near its peak output anyway secondly the inverters are more efficient when they're operating at the top end of their range and thirdly the inverter will be cheaper to buy this strategy is called oversizing and in the case of solar edge the array size can be up to twice the size of the inverter so the six kilowatt inverter on the right is able to support an array of up to 12 kilowatts peak one important thing to note is that if your inverter is too small there might be times when your home requires more power than the inverter can provide and unless there are other sources of power available to meet that extra demand the grid will end up supplying that power potentially defeating the purpose of having solar in the first place for example using a 5 kilowatt tumble dryer with a three kilowatt solar setup will always draw two kilowatts from the grid one final aspect to consider when sizing your inverter are any permissions required from your national grid provider regarding the amount of power that your inverter can export to the grid in the uk provided that the maximum power that can be exported by your inverter is less than 3.68 kilowatts then your installer can complete what is known as a g98 application on your behalf and this will automatically be approved by your local distribution network operator however if your inverter is able to export more than that then your installer must complete a g99 application and only proceed if the application is approved by the dno some applications may require you to pay a monetary contribution to the network to support your setup which could be hundreds of pounds and some applications may be rejected there is another type of application that can be made called the g99 fast track this is where the inverter is able to generate more than 3.68 kilowatts for use in the home but it will limit the export to that amount such applications are approved quicker and easier than a g99 but bear in mind not all dnos provide this fast track option thanks for staying with me so far if you're getting a lot from these videos and would like to see more please can you help me and hit like on this video and subscribe to my channel thank you okay we're ready now to look at the third main area of investment the battery if you watched my previous video you may remember this graph showing typical daily electricity consumption and how solar energy is generated throughout the day to meet some of that demand to cover the times in the day where there is no solar energy we can essentially move some of the unused solar energy elsewhere in the day to those times using a battery solar batteries come in all shapes and sizes there are lots of brands and some batteries are certainly better looking in the home than others and the larger batteries can weigh in at more than 100 kilograms each one of the early decisions you'll want to make then when purchasing a battery is whether you want an ac or dc coupled battery looking at our example solar installation again we will now add a dc coupled battery to it batteries are dc by nature not ac and so we can add a battery into the dc side of a special type of inverter called a hybrid inverter this type of inverter will charge the battery with any excess power coming in from the panels not required for the home instead of exporting that power back to the grid and when there is not enough solar available to power the home the inverter will discharge the battery to meet that requirement until the battery is empty at which point the grid will take over instead of a dc coupled battery we can add an ac couple battery to our setup like this this type of battery connects directly to the ac supply and can make decisions itself when to charge and discharge based on the continual monitoring of both the inverter and the grid supply a key difference between the two types of battery is their overall efficiency as each time there is a conversion from ac to dc or vice versa around three to four percent of the power is lost let's look at this for each type of battery for a dc coupled battery the solar panel generated is dc so this can flow straight into the battery it's only when the power comes out of the battery that it's converted from dc to ac before going into the home a single conversion for an ac coupled battery the dc solar power generated is converted to ac to reach the battery in the first place but then it has to be immediately converted back to dc so that it can be stored in the battery and when power comes back out of the battery it's converted once more from dc to ac before going into the home that's three conversions which might equate to 9 to 12 percent loss of power let's take a look then at the pros and cons of each type of battery the dc couple battery is cheaper than an ac coupled battery as it does not require an additional inverter and it's more efficient because there's only one ac to dc conversion however it does require a more expensive hybrid inverter and the choice of battery may be limited by the manufacturer of your inverter and it may not be suitable for backup supply unless your inverter specifically supports that option an ac coupled battery will work with any inverter and it can be more readily be used as a backup supply in the event of grid failure however it is more expensive than dc coupled because of the extra inverter required it's also less efficient requiring three ac dc conversions and depending on your dno it may require g99 approval batteries can be a great addition to your solar setup they not only allow you to shift solar energy as i described earlier but during the winter months those batteries can also be used to store cheap energy purchased overnight to be used the next day when the rates are much higher batteries are expensive though and the return on that investment is not as high as your solar array not least because batteries might only last 10 years it's definitely worth you getting the calculator out to make sure a battery will work in your situation so we've covered the three main elements of a solar installation there are a couple of optional elements then that are proving extremely popular in many installations around the world the first of these is a solar diverter there are a few manufacturers of these devices here are three of the most popular a solar diverter is a clever device that is connected to say your gas-powered water tank and it constantly monitors how much power your solar panels are generating and it compares that to the power that your home requires if there is any spare power that would otherwise be exported it uses that power to heat up the water in your tank another very popular device for your solar installation is of course an ev charger now you might not have an electric vehicle today but in five to ten years you're likely to have one so it's certainly worth considering to get an ev charger put in at the start like the solar diverters ev chargers are clever and can divert excess solar power into your electric vehicle during the day saving you a great deal of money over time to finish up then just a few words about choosing an installer home solar is starting to grow rapidly all over the world and like any new market there will always be a few cowboys entering it all trying to make a quick buck at your expense and there will be some well-meaning startup companies who will be learning as they go along potentially using your installation for that purpose how do you best protect yourself against getting ripped off then well here are some tips to help you did you contact them or did they contact you treat any company that contacts you out of the blue with caution they may be going for a pressurized sale before you've had a chance to check them out properly is your installer able to provide evidence of work done to date ideally in your local area that you can check out yourself are they mcs or heis accredited in the uk these schemes are there to help you be suspicious if your installer isn't a member of these schemes check out their trust or trader or similar online review site ratings check for plenty of detailed reviews over a period of years look into the company on your country's company register in the uk that's company's house have they been in business long have any of the directors been involved in other solar businesses that have ceased trading for example how much payment do they want up front 20 to 25 is typical if they want more than that best to go elsewhere always try to pay at least part of the installation with a credit card even 100 pounds this will give you what is known as section 75 protection meaning that the credit card company is jointly liable if things go wrong how detailed is the contract if it's only one or two pages then you could be opening yourself up to trouble as there's not enough detail about what the installer is signing up to provide finally don't be afraid to check out installers online there are plenty of online forums for example on facebook where you can ask questions or even get opinions on quotations that you've had if you do use these forums don't just take from them but give something back perhaps a post later on about your own installation and your experiences that could help others okay i hope you found this video useful as you go to market for your solar solution confident that you'll make the right decisions and not end up wasting any money please share this link with any of your friends that might be interested in going solar and if you hit the like button this video will get more exposure on youtube which will hopefully help others thanks for your support [Music]

Channel: Gary Does Solar

Views: 334,967

Keywords: solar, panels, home

Id: ccm1HmxELlQ

Length: 25min 39sec (1539 seconds)

Published: Sun Jul 10 2022