Solar power is difficult and expensive but is the better choice for many uses. In sunny Australia, solar power is close to the default power source with power storage the real sticking point. Hydroelectric storage, the current best storage, is coming to towns near you.
Conversion of sunlight to electricity is not efficient, the maximum power you get is about one third of what hits the solar panel. From there on, electrical energy is efficient when used immediately. You lose power when pumping the electricity into any form of storage for later use. You lose more power when extracting electricity from storage. And things get worse from there.
The storage component is the most expensive part of a solar power system. If you are forced to resort to a lithium battery, you are destroying the green aspect of your solar power by using an explosive poison that is expensive and needs frequent replacement. Lithium is a failure.
The biggest cost/waste is storage and the most effective home based storage is a small battery to cover your overnight lighting requirements. For anything longer term, you need community based storage using something better than lithium.
The next biggest cost/waste is installation and that is reduced when the solar project is part of something else. Are you building as new home? Install solar as part of the project. All the wiring will be part of the standard house wiring. You will not need to duplicate scaffolding or anything else. A project that is effective as part of a new build, or as part of a major renovation, may be too expensive as a later modification.
After the battery, the next replacement item is the converter. Expect it to last only 10 years or 5 years or less. This is one place where you should pay full price for a full 10 year guarantee.
The actual panels have dropped to a point where the cost of the silicon is minor. Guarantees are 20 years, 25 years, or 30 years. What you have to look at is the level of service at the end of the guarantee. A good guarantee might offer replacement if the power output drops below 80%.
Overall, at the end of a 30 year guarantee, the controller will be replaced 3 times (10 year guarantee) and the battery might be replaced five times as a 10 year battery guarantee might cover only 50% power across those years.
Lets compare a success to a failure. Your project is probably somewhere in between.
A friend installed a small solar array with a smaller lithium battery on the morning sun side of his house. There are no buildings or trees close to that side which means the sun will never be blocked. The fresh electricity is used immediately in a washing machine and other appliances. The system is designed to supply all the power they need for that peak morning use in winter. For the rest of the day, the panels charge the battery that lights up the house at night and runs the kitchen for a little bit of cooking. On a busy day, the system exactly matches their use.
On many days there is no washing machine use or no cooking in the kitchen. The battery is charged then the excess is sold into the grid. The sales to the grid help pay for the system. The real saving is not paying for electricity on busy days.
So what are the important elements of success? Their solar array is located in the right spot to handle their peak usage in the least sunny days of the year. They are protected from a development on that size of the house. They do not need a mass of electricity at night. Their system is sized to supply what they need most days, not a massively oversized every day system.
Another success is shops with big refrigerators and air conditioning. The maximum heat is during the day when there is maximum solar power. The maximum customer activity through the front door is during the day. The maximum opening of refrigerator doors is during the day. Another case of matching the solar array output to the power you use across the day.
What do failures look like?
You buy a Tesla electric car instead of a the many better alternatives. You drive the car during the day which means you charge at night. You have to buy a huge solar array feeding into a huge battery store and you are talked into buying a Tesla lithium storage battery. You lose power pumping electricity into the storage battery then you lose more power pumping it out for the car. You lose more power pumping the electricity into the car battery then lose more power pumping it our. Both batteries degrade every time you use them.
Everything has to be oversized to handle all the loses. Everything has to be oversized to allow for the battery capacity falling every day. You have to replace the battery every few years, a massive expense, and a pollution problem far worse than many of the alternatives.
The day after you install the solar array, your neighbour builds a tall building or plants a big tree that will shade your solar array during peak times. There are no solar access guarantees in Australia. You cannot protect your supply of sunlight.
If you own an electric car and the company, a better approach would be to install the solar panels at work and charge your car during the day direct from the panels.
What do we need to do for the best use of solar power?
Most areas of Australia have excellent sunlight. The first problem is the supply to individual buildings. You can get a good supply in the middle of the day. For peak usage times, often early in the morning and late in the afternoon, your supply can be blocked by trees and buildings. The modern approach for suburban areas is to plan at the housing estate level. You can then get together to place the panels on the best sides of the best roofs, share the cost, and share the power.
You can also share storage which means you can afford one of the liquid battery systems. While the liquid battery systems start at a higher price, they are cheaper to expand to the size you would share among dozens of houses. A community battery does not have to use lithium, you can use something modern, clean, and safe.
At the city level, you can use hydroelectric storage which is the cleanest way to store energy. The initial cost is higher but the expansion cost is lowest, a good reason to build this type of storage at the city level. There are currently tens of thousands of proposed hydroelectric storage projects under investigation in Australia. If just one tenth of them go ahead, they will store more power than all the Tesla Powerwalls in the world.
Sydney is in the Australian state of NSW, New South Wales. The NSW government initially subsidised solar panel electricity by an excessive amount due to the stupidity of the Labor party in power at the time. Many solar arrays were installed in the wrong places. The stupid government was replaced by a government that actually thought about things before acting. The solar subsidy reduced to an amount that encourages the installation of efficient solar arrays in the right locations.
The new government mentioned that most existing arrays were pointed at the midday sun when electricity production from the array is at a peak but the use of the electricity is at a low. What is really needed are more arrays pointed towards the afternoon sun when use is at a peak. One day in the future we might get a solar power subsidy with variations across the day to match the power supply to use. Either that or massive hydroelectric storage to trap that midday excess peak supply.
The Tesla model 3 is ramping up in production fifteen years after Tesla said they would revolutionise the world with electric cars, 10 years after Mitsubishi introduced a mass production low cost commuter car and 9 years after the Nissan leaf revolutionised the world, setting records for sales of affordable 100% electric cars.
The first electric car was on the road 181 years ago. While the Tesla is slightly better, Tesla still use ancient chemical batteries and have no option to run on biofuel. General Motors, that evil big corporation, entered the 1987 World Solar Challenge, a race across Australia for 100% solar powered vehicles, and won with the best design. GM were limited only by the cost of the rechargeable silver oxide batteries. You would have had GM electric vehicles then if they had carbon capacitor storage or any of the other new storage technologies.
Commuting distances in Australia are up to tens times longer than the commuting distances in the countries where smug journalist write about electric and hydrogen fuelled cars. In 1996, GM released the EV1 with a range of 255 kilometres, the first electric car with a useful range for Australia. The price was the same as Tesla charge for their model 3. Unfortunately the EV1 was as rare as the Tesla 3 due to the same problems, the production difficulties and the lack of charging stations and the installation cost for a home charger with a useful current supply. Australians rushed into hybrids because you can actually use them for full length trips without the massive overheads.
Every car manufacturer, other than Tesla, has a mixture of electric and hybrid cars. Petrol engines can run on pure ethanol distilled from plant juice. Australia and Brazil both produce masses of sugar. Both countries produce ethanol for fuel. Some cars in Brazil run on 100% clean green ethanol and those same cars are on sale in Australia. In the sugar producing areas of Australia, Australians could commute using 100% clean green ethanol if the various Australian governments would actually start doing things for Australians instead of just sucking up to foreign companies.
The clueless inner city greenies should use public transport and leave their fashion statement Tesla's to rot in a cave where the lithium from the batteries and the carbon dioxide from all the plastic cannot leak out. Outer city and country folk should be allowed to enjoy their journey appropriate hybrids and have access to 100% ethanol fuel or biodiesel, as required. The people in between can buy one of the many full electric models from all the other car manufacturers without paying the Tesla fashion statement tax or waiting many years for delivery.
A good solar power system includes a Wifi connection to feed information to your computer so you can match your usage to production. You can then set the automatic start timer on appliances. This level off information supply should be a minimum standard for all solar systems. Battery packs should feed the same level of information, their charge, their charge rate, and their deterioration after each charge. You can then plan the battery replacement and compare brands/chemistries with other users of similar size systems.
The data flow from solar systems could be aggregated and published to show the most successful choices to future buyers. Some companies offer systems selected by them and aggregated by them but do not publish the results. The current choice is to sign up with an aggregator, where they take the risk, or use generic information about your area but not a detailed match to your house and your use.
For less than $200, you can put together a solar pack with a built in computer to record your solar energy supply on your roof. Mass manufacture would make the device less than $100. You should be able to rent them for about $30 per year. Put one up on your roof for a year. You could get an accurate readout for your roof in situations where there is some shade from trees and other buildings.
The same kit could, for very little extra cost, include measurements of temperature, humidity, wind speed, and wind direction. From their, you could work out the most efficient air conditioning, the best rainwater collection and water management, everything you need for comfortable livable an environmentally friendly house using the minimum energy to fix typical problems in Sydney and similar cities, reduce extreme temperatures and remove excess humidity when there is extended rain.
Solar power is affordable and useful when matched to your house and your use during the day. Storage cost is the big factor and is dropping steadily. Based on details of your house and your exact use, you might benefit from something other than a minimal battery plus a bigger array to feed the bigger battery. Hydroelectric storage and the next generation of batteries, free from the explosive poison named lithium, will solve the storage problem.