Prepared by Skyler Kah & Blake Seufert
Solar Installation 2016
In June 2016 McKinnon Secondary’s monthly electricity bill was $10,959.58, representing 87.94 tonnes of CO2 emissions.
I think we can all agree, climate change needs to be tackled and it is not a hoax perpetrated by the Chinese (Trump said that!). The school's journey to provide its first solar powered energy source started with all of the students at Mckinnon Secondary College who voted for the allocated $10,000 the school council receives every year to be spent on solar power. This grant was handed over to me and I was set the task to organise the installation.
I started by doing some research into the types of solar panels and inverters. The panels convert the lovely sun into DC electricity and the inverter turns that electricity into AC power our appliances can use, plus it tells us how much energy we are producing. There are many factors that affect the price and quality of solar systems and some specifications matter more than others. I had to investigate which system will last the longest, have the best value for money and which will produce the most amount of power. Although a $10,000 solar system will only provide approximately 2% of the school's peak electricity needs, the educational benefits, community awareness, and making the first step in providing green power is a great start..
The first company I contacted was very reputable and had previously installed solar on parliament house. They wanted to install a system so large, the whole school could power itself but this was too far out of our budget (although this system could be paid back in only 8 years).
The next six companies I came into contact with actually reached out to me first because I had entered my details online to some sites where they would connect solar companies to me. The proposals I received ranged from a 5kW system to a 9kW system and all had different combinations of panels and inverters.
Three of the companies came into the school to discuss their quotation with Blake Seufert, Mr. Farthing and I, and all assured us that they have the best quality panels available on the market. WIth research we learnt that we needed to choose large panel and inverter production companies, so that they will still be in business to uphold our standard 25 year warranty for the system. Furthermore, we needed to ensure that we had an inverter that could provide us with accurate energy production statistics because part of our goal in our Carbon Free Classroom (CFC) initiative is to determine the most effective ways of reducing a school’s carbon footprint. We can use this data to demonstrate how to achieve this, and it provides an easily accessible education tool for all Mckinnon students.
After collating all of the quotes I received into a Google Document, I presented the options to the CFC group at one of its meetings. We decided to go with Satellite Solar who were prepared to install a 9.1kW system including GCL Tier 1 panels, a Fronius inverter and an aluminium mounting set so that the panels are tilted at approximately 38° to the horizontal and are facing as close to true North as possible.
A challenging part of this process was telling other companies that they were unsuccessful, once we had chosen Satellite Solar to install the solar PV system at Mckinnon Secondary, and giving supportive feedback to help them secure a deal later on.
All up, it took about four months from receiving the first quote to the installed, working and running system.
Being in a family who are environmentally conscious, where we have solar panels and a plug-in hybrid electric car, has definitely made me increasingly aware of ways to reduce our impact on climate change. This is why I am passionate about the environment we all live in and why students at McKinnon and I believe we all need to focus more on ways to at least slow the process of global warming.
Challenges with Solar
Carbon Free Classrooms mission is to not only reduce dirty energy usage but to do so in a way that will save the school money. In order to be successful in our vision we need to look at how schools buy energy.
How schools pay
Schools tend to buy power in groups. A school system (government, diocese, etc) will typically approach a power company and purchase electricity in bulk. This means schools get a tremendous deal. Our school can pay around a $0.10c per kWh, with your average domestic house paying around $.30c to $.40c (avg of on and off peak).
A Residential Example
Typically when you purchase a solar array, for example if purchase a $10000, 10kw system . A 10kw system will produce around 30kw/h of power a day (confusing i know). That means we can work out how long it will take us to get our money back (assuming we use all of that power).
For a residential system where power costs us (at best) an average of $0.30c per kW/h we need to take 30kW/h we generate and multiply by $0.30c means we save $9 per day. If we take the total cost of the system ($10,000) and divide it by the amount we save each day ($9) we get: 1,111 days! In other words just over 3 years for us to have saved the cost of the system we installed. Every day after that 3 year period we effectively make $9 profit (money we don't have to pay to a solar company).
- Great result if you're in a house paying $0.30c per kW/h.
Lets take the exact same example of a $10,000 10 kW/h system that generates 30kW/h per day. If we do the same sums with the 0.10c per k/Wh we only save $3 per day. So to pay back $10000 at $3 a day it'll take 3,333 days or 12.5 years before we break even!
- Risky proposition of a 12 year payback before making any profit! A lot can change in 12 years.
There are of course other considerations like:
- Cost of power changing
- Off peak vs on peak usage
- Making sure the power you generate is being used and not re-sold to the grid for a fraction of that cost. (currently around $0.04c)
- Solar equipment will always experience loss through the inverter, cabling and panels not being 100% as efficient as they claim.
- The grid is starting to go solar on a large scale which can be produced cheaper at scale than we can produce it
This means, for solar to make financial sense we need to be smart with selecting the right solutions that will fit our needs.