An Analysis of grid connection and off grid Solar energy for Alberta

In the renewable energy sector, there are differing opinions on what the best way is to utilize solar energy. This discussion will focus on Alberta, (other areas of the country will likely have a totally different result depending on the energy mix, local climate and human factor of electricity use).
To help understand the discussion the following two charts will help (Also, click here to look at the article on the Alberta energy mix)

This chart shows the demand on the grid in summer based on the hour of the day.

Notice on this chart that the peak usage is at a time when solar would produce well, although the solar contribution may be a bit marginal in the last couple of hours of the peak, it benefits peak demand.

The following chart shows the winter demand on the grid.

One very important thing to note here is that the peak demand comes at a time when no solar is available. Also, the peak demand is slightly higher than the summer demand.

In both instances, the solar will benefit us by decreasing the amount of natural gas burned. Coal usage is not affected by solar on the grid since coal supplies the base load only and coal fired generation does not respond quickly enough to be adjusted for renewable energy input.

The result of grid-tied solar systems then is to reduce the amount of natural gas being burned, but these systems do not reduce the required capacity of either the generation plants or the transmission system since the peak demand happens when there is no solar available. Even a net zero situation makes no impact to reduce total natural gas generation infrastructure nor relieve demand from the grid since net zero becomes a consumer at this peak period.

What other alternatives do we have? Properly designed and installed off grid systems without backup power or heat, such as our facility here in Didsbury actually reduce both the amount of coal and natural gas burned for electricity and heat as well as the demand on the electrical grid, since it is not connected to it. The benefits of this type of system then are that expensive transmission capacity would be reduced and grid generation capacity could be reduced or not need to be expanded. Poorly designed or small systems may need to run a generator a lot and would therefore not be very beneficial to the owner. Even a well designed system with a backup generator can be quite good since the gas is burned at either the generating plant in the case of a grid tied system or it is burned on site. Either way, gas is burned, but in the off grid case, there are no line losses and most likely, the owner will be more careful in the energy usage to keep from running the generator as much. A more advanced concept that can be mentioned here would be to charge these "Off Grid systems" that need supplementing off the grid at non peak hours, thereby utilizing present generation and transmission capacity, but not increasing it. It would also allow better dynamics in our generation capacity and be beneficial to power suppliers by helping to removing peaks and valleys in power demand. Although of great benefit to every one, this scenario would be difficult to implement in alberta since privatization has destroyed the authority and unified structure needed to plan, set incentives and co-ordinate such a project.

While everything that mankind designs and makes will fail at some point or other, our experience here has been that our off grid systems have been more reliable than the electrical grid. We have not had a single power outage with our off grid system in the many years that we have used it, but the grid has been off many times since we went off grid. That being said, when you have your own power system, you now have the added responsibility for maintaining and fixing it if something does go wrong.

Each person will need to make their own decision based on their values as to what suits them best. This article merely seeks to give information for that purpose.

The largest impact that a building has on the electrical grid is not in fact the building, but rather the habits of the occupants.

a. Energy usage and usage patterns need to be assessed in order to reduce overall consumption and maybe even more importantly, energy demand.

b. Appliances and other devices need to be analyzed for efficiency and possibly replaced or modified.

The heating system is one of the largest consumers of energy in a home. Here again, efficiency and demand need to be assessed in order to reduce both the total consumption as well as the demand.

The type of heating system is likely the next item to look at in terms of the electrical grid. Since the electrical grid is operating close to capacity, heating systems that increase the usage or more importantly the demand on the electrical system should be avoided. In terms of electrical demand only, resistance type heat is the worst way to heat. It drives up the demand on the generation and transmission at a time when the system can least afford it. Heating systems that use large pumps are likely the next worst offender for our grid, since again these units place a higher demand on the grid when it can least afford it. After this would be gas fired forced air and likely the best for the electrical grid is a well design gas fired Hydronic system. (some Hydronic systems can use a lot of power because of poor design and control)

The construction of the building, mainly the insulation and air infiltration, likely then has the most impact on the amount of natural gas burned. If the building is insulated well, whatever heating source is used will not run as much and will be a smaller load. As mentioned above though, in terms of demand on the grid, building a really well insulated house and putting resistance type of electrical heat into it will likely increase the demand on the transmission system but probably reduce the overall consumption.