Off Grid Living Without a Generator Solar Powered AC Coupled Micro Grid © Boyd Solar corp. Didsbury, AB

Off Grid Living Without a Generator

Solar PoweredAC Coupled Micro Grid

© Boyd Solar corp. Didsbury, AB www.boydsolar.com

©Boyd Solar corp. Didsbury, AB www.boydsolar.com

The short answer is yes, but…..

Is the Sun all you really need?


“Off Grid” people usually have different motivations than “On Grid” people

Energy Independence and SecurityFear of Electricity prices rising substantiallyGrid is too far awayHave the money now, I will prepay my Electricity Save Money – (depends on where you are)

Motivations


Different designers, dealers and customers size the systems differently.

Some design so that the upfront cost is low in order to make the sale. This will usually result in a much higher total cost and much frustration during the life of the system.

Generally this approach will require the battery banks to be replaced much more frequently, require more frequent generator charging and maintenance of the batteries and the accompanying time.

Designing the system for a minimum of maintenance and longevity will generally provide the best value and provide for a positive experience with the Solar Power System.

Sizing


Well, most of the time, this is the starting point

Where do we start?


List all the things that we would ideally like and expectSize and design of the HomeGarage?AppliancesHeating systemLifestyleGenerator?

The Wish List


This usually entails doing an energy audit and filling out an energy worksheet

Most people will need to start by learning some basic electricity

So let’s look at an example

Tally up the Power Requirements


We have lost the direct correlation of energy consumption to input

How much energy does a small heater use and how much solar power would be required to provide this?

It takes 12.5 Amps at 120 VoltsPower = Voltage X Current= 1500 Watts or 1.5 KWRunning 24 hours then1.5 KW X 24 = 36 KWHNo problem right?

Energy


So….The average Calgary home uses about 21 KWH per day mmm……A typical Solar module is about 250 Watts, so how many do we need

to run this little heater in the winter for 24 hours on average in the Winter?

Energy


So what size of battery bank would be required to store this amount of energy for 1 day

Since we do not want to discharge a battery bank more than 50%, we would need a minimum of 72 KWH available

The Rolls 2KS 33 in a 48 Volt configuration would have a maximum rated capacity of a about 83 KWH based on the 24 hour rate, thus this would be the minimum

Energy


Now if we wanted to have 6 days of Autonomy

Energy


So….How much natural gas then would it take to generate the same

amount of heatWell……1 KWH = 3412 BTUTherefore 36 KWH = 122832 BTU122832 BTU = .13 GJPrice per GJ of Gas $ 2.828 on the last billPrice then for using natural gas is about 37 cents (plus of course

all the “other charges”

Energy


Energy efficiency is the first place to start Windows and doors usually represent a very significant

percentage of the energy that is lost in a home Heating system – what type? Fridge, Freezer – usage? – location? Lighting

1. Technology2. Quantity3. Type

A. AreaB. DirectionalC. control

Energy Efficiency


The Solar Array


The Racking for the Array










To Track or not to Track


The Batteries


The Batteries


Proper Battery Charging Proper battery charging is crucial to

obtaining maximum battery life The top picture shows the charging

current on a sunny day in March. The absorb cycle starts at about 10:00 AM and is done at about 1:00 PM

The bottom picture shows a heavy overcast day at the end of March. The absorb cycle here starts at about 11:15 AM and does not end until about 4:00 PM.

As is obvious from this, a properly sized system will charge the batteries properly even in bad weather and avoid sulfation of the batteries, which would really shorten their life and be expensive.


The Inverter


The Generator


Cost Analysis


Cost AnalysisIn looking at a cost analysis, we need to remember the initial

motive for going “Off Grid”, so the monetary comparison is not the only factor

The location of the system in contrast to getting a “Grid” supply is going to affect this.

That being said, let’s continue.A good “Off Grid” power system is going to run roughly $

10.00 per Watt, so 12,000 Watts (12 KW) is going to be around $ 120,000.00 installed

We’ll continue after we treat you for the heart attack


Cost AnalysisFrequently, at this stage we get


Cost Analysis…that is why we start with energy efficiency and very

carefully looking at all the loadsThe “Boomer” system would be used for a load demand of24 KWH per day if used in conjunction with a back-up

generator or 8 KWH per day if used without a back-up generatorFor this analysis, let’s assume the latter and a lifespan of 15

Years on the batteries. (the other components will last longer)8 KWH per day then comes out to 2960 KWH per Year


Cost AnalysisSo…..2920 KWH per Year, if you are on Grid, at the present rate will

cost about $ 650.00 per year or a total of just under $ 10,000.00 for 15 years (without accounting for inflation and other factors)

Replacing the batteries will be about $ 30,000.00 after 15 yearsSo, the cost per KWH in the first 15 years would be about $

120,000.00 divided by 43,800 KWH = $ 2.74 per KWHIf the monetary payback is the only consideration, then the only

places that these system make economic sense are in locations where power would be very expensive, such as remote locations that would otherwise need to have a generator running 24 hours a day


Cost AnalysisEfficiencyCareful planning of loads and appliances, especially the

heating systemLifestyleResult is a smaller required system, therefore, less expensiveWith proper planning and lifestyle adjustments, people can

live fairly comfortably with a $ 40,000.00 system, but generally don’t expect to be on the low end of the price range


Living Off Grid can range anywhere from a couple of Solar modules to power a light and maybe the odd other thing to a home where you would not even know it is Off Grid.

Generally speaking though, normally a small adjustment in lifestyle and building a very energy efficient home will allow for a reasonably sized system where there is very little difference in living from a Grid connected home.

Just for example, we cook with electricity, run computers, all sorts of tools and most things that people would normally use

Most of the time, it comes down to how much space is available and how much money the person willing to spend

Living Off Grid


Challenges


Check the motivation for doing so againCheck the options and costsWillingness and/or ability to understand electricity and the

systemWillingness and/or ability to maintain itWillingness to live within the capability of the chosen systemRemember, this is a power plant that you are purchasing, and

just like any other power plant, there are maintenance costs, both in terms of time and money.

Servicing by a professional will tend to be quite expensive, just like it is for the Grid generators and wires owners.

Is Going “Off Grid” for me?

Off Grid Living Without a Generator

Solar PoweredAC Coupled Micro Grid

© Boyd Solar corp. Didsbury, AB www.boydsolar.com

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Off Grid Living Without a Generator Solar Powered AC Coupled Micro Grid © Boyd Solar corp. Didsbury, AB