Written by Nani Pradeepan, P.Eng.

 

Depending on the type of property and where it is located a specific type of solar electric system that best suits for the needs. Depending on where a property is located – in the heart of a city, in the suburbs or in the woods an appropriate type of solar electric system installation must be implemented.

Location is the key characteristic as grid availability and distance from the grid will be determinant in choosing the type of system best for a given property.

There are basically three types of Solar Electric Systems:

Grid Tied Solar Systems, Grid Tied Solar System with a Battery Back-up or Hybrid Power Generator, and the Off-Grid Solar Power System.

Grid Tie Solar System:

This is a very common type of installation for cities and suburbs with close proximity to the electric grid. In this system, the PV installation is connected to the grid and two meters or one two-way meter may be installed to measure the flow of electricity to and from the grid.

In Ontario residents participates in Micro FIT program need to have two meters to measure the flow of electricity and the Ontarians participates in Net metering program need to have one two-way meter to measure the flow of electricity.

The advantage with Grid Tied Solar System is that the PV installation need not necessarily be seized to meet all the needs of a property. If demand surpasses supply at any one time especially in peak hours, electricity is simply pulled from the grid to make up. This situation is reversed when the capacity of the installed Grid Tied Solar System is high enough and produces more than needed electricity. The extra electric power is pushed or back-fed into the grid which produces credits the consumer can then use at periods of low production such as at night to offset their power consumption.

Grid Tie Solar System with Back-up or Hybrid Power system:

Grid Tie Solar System with Back-up system differs from the above described in that it has a battery or power generator to provide power during grid outage. Grid Tie Solar System with Back-up best suits areas without a reliable power grid. Our solar engineer design the system to store some of the electricity produced when production exceeds demand for use when the grid goes down. This type of system can also incorporate an electric generator for the same function.

Off-Grid Solar Power System:

Off-Grid Solar Power System is for locations without traditional electric grid. It best suits for properties located in the woods, mountains or remote areas of the developing world with no electric grid.

Off-Grid Solar Power System also incorporates the battery and the power generator in its design. Instead of using a battery or generator as a back-up as in the previously described system, it is used as a necessary component.

The battery is used to save electricity produced during the day time to use in nights and during rainy/cloudy days. A generator is provided in this case when the battery drains out due to continuous use and in days with no low power production from solar.

Use of these systems depends on location and it is important to note that in each design, convenience and efficiency will vary significantly depending on the use and location.

Now you know more about solar electric system types–which of these would best suite your needs depending on your location? We can help you pick the best solution for your need and location; do not hesitate to contact us with any questions you may have.

Written by Nani Pradeepan, P.Eng.

Inverter

We know that solar panels produce direct current (DC) electricity and our utility grid is powered by alternating current electricity (AC). Inverter used in solar power system converts solar DC electricity to AC electricity we all use at homes and other buildings.

As solar panels are rated at standard test conditions and not all installation locations and situations come close to these test conditions. Hence it often makes sense to oversize a solar array relative to inverter rating. This enable for greater AC electricity harvest when production is below the inverter’s rating, which is typically for most of the day and also can results in clipping.

Inverter clipping

Every inverter has a maximum rated power and it will generally never output more than their max-rated AC power. This is very important as the component ratings of the power electronics in the inverter are designed with a specific power and voltage range and the grid connection points in the buildings are designed with a specific max power limits.

When the DC solar array is generating the most amount of energy that is greater than the inverter’s power rating, the “extra” power generated by the array is “clipped” by the inverter to ensure it is operating within its capabilities. This leads to a flat line in the green curve in the figure below, and capping the power at the inverter’s nameplate power rating during peak production hours and known as inverter clipping.

The purple line in the figure shows a typical bell curve of AC output power peaking at noon, just below the rating of the inverter indicated by the dashed line. If we increase the size of the solar array by adding more panels, which increase the DC-to-AC ratio of the system (as illustrated by the green curve), we can harvest more energy throughout the day. The area between the green and purple curves is the energy that is gained by increasing the DC-to-AC ratio.

Standard test condition temperature is 25ºC but solar panels are hotter than 25ºC when the array is receiving maximum sunlight. Higher than rated temperature of 25ºC results in loss of power production when solar panel receive maximum sunlight. In other words the solar array produces less than the rated power when solar array receive maximum sunlight, this reduce the losses due to clipping of inverter.

Written by Nani Pradeepan, P.Eng.

As the cost of a solar installation come down people are looking for choices for their solar systems. One of the choices people look for is a solar PV system with minimal deviation to the appearance of their house.

Solar roof shingles are one way to turn a traditional shingle roof into an energy producer. Solar roof shingles are a new green roofing product of the past few years. Solar shingles like traditional solar panels use the sun light to create electricity. Each of the solar shingles is comprised of photovoltaic cells and each shingle is a small PV module that has to be connected electrically in series to reach the DC voltage needed by the inverter which converts the DC electricity to commonly used AC electricity.

The typical DC input voltage for inverters is 350 to 500 VDC. That means many shingles need to be wired in series. This requires long strings of module to module connections wires that are all hidden beneath the finished roof and difficult to access.

When one module or its connection fails, all the modules in the string go out just like in Christmas tree lights. A service tech has no easy way of knowing which shingle is defective. A big portion of the roof often needs to be taken apart, and all components tested. Then, if matching replacement solar shingles are available, the array may be able to be reassembled.

PV shingles have been nailed or screwed into place as the PV shingles marketers wanted to entice roofers to be installers. However, roofers do not have the understanding or the necessary training to install solar-electric systems. If there is an electrical arc caused by a faulty shingle-to-shingle connection, it could start a fire in combustible tarpaper and wood roof sheathing.

Solar shingles are less efficient than traditional solar panels meaning need more roof surface than the traditional solar panels. Rated output of solar shingles is about 12 watts per square foot; whereas today’s best crystalline modules offer about 20 watts per square foot. Since solar shingles are installed on the roof deck there is no back-surface convective airflow, the all-black solar shingles run hotter than conventional solar panels, meaning further lower efficiency and possibly shorter product life.

PV shingles have been a transitory product. How long will companies selling this product keep producing them? For example, after five years, Dow ceased manufacturing and distributing solar shingles. There is no long-term experience with solar shingles products and they may or may not last. Will the warranty be supported over twenty five years as with traditional solar panels?

Even if the company and product is still available, will it be in the same form and electrical configuration to allow replacement? With all these uncertainties at present solar shingles are not prudent options for a green roof.

Currently, there’s no mass produced solar PV shingle solution for retrofit. If your house has a black roof, using conventional black-on-black modules installed flush with the roof may offer the best acceptable solution. Standard framed PV modules have been proven, reliable and productive, and we know how to install them well for the long term. For many people, the solution is to accept the beauty of a product that will produce clean electricity reliably for 40+ years.

Written by Narayana Asogan, P.Eng.

Water is a rare commodity. Superficially water is very abundant – about 71% of Earth’s surface is covered with water. However, 96.5% of it is salt water in the seas – not good for consumption as it is. Balance 3.5% are in fresh water lakes, glaziers and polar caps. 69% of the fresh water is in the form of ice (solidified water), meaning 2.4% is in liquid form.

Canada has about 20% of world’s freshwater and a low population – only about 0.5% of world’s population. Thus it is very tough for a Canadian to understand scarcity of water.

However the available fresh water needs to be treated before it could be said to be fit for human consumption. Municipalities treat the water before storing and delivering to the households and industries. Households and industries discharge used water into the sewers, which the municipalities transport to treatment centres, treat the sewers to a level acceptable to return to fresh water system, from where it undergoes further treatment to make suitable for human consumption and stored and delivered.

All these transportation of water, treatments, transport of sewers, sewer treatment etc. etc. requires quite a lot of energy and infrastructure. And costs of operation and maintenance of the infrastructure and cost of energy adds to the cost of water delivered to us.

Let us do some math to see what kind of savings is possible financially for a building by water conservation in just one area of water usage. Consider a multi-unit residential building of 100 apartments with an average occupancy of 3 per household. Let us say the building is with older water guzzling toilets from around the 90’s – about 15+ litres/flush. On the average 1 person would flush a toilet 5 times per day. Based on the above basic data on occupancy and flushing of toilet, if the toilets were replaced with newer 6 L/flush, about 5,000 m³ of water could be saved from flushing down, and the building management would save about $ 17,000 per year on water bills. Further savings are possible with dual flush toilets, low flow shower heads.

Example of toilet is considered for water conservation as it is estimated that about 47% of household water consumption is by the water guzzling toilets of 15 L/flush. Low flow faucets in kitchen would not contribute much savings as filling a pan would take longer with low flow and may not contribute much for saving.

At one apartment level one could see a substantial water saving and financial saving to the management. At the level of the municipality which serve several such communities water saving and the associated energy savings would be enormous.

In today’s world where energy conservation, reduction of CO₂ emission, Carbon footprint reduction are essential, water conservation also become an essential component in energy conservation equation.

New Dawn Energy Solutions have the expertise to study your electricity, gas and water usage and arrive at cost effective solutions to reduce energy consumption, Carbon footprint etc. NDES is a vendor neutral company and will look for the best solutions to your needs.

Written by Nani Pradeepan, P.Eng.

Electricity is a commodity regardless of the how it is generated from different resources by different suppliers. But like many commodities, the cost of electricity varies depending on the time and location it is delivered.

Utilities pay as low as $0.04/kWh for electricity generated in centralized plants but the average charge to consumers is $0.17/kWh. Why such a big range between wholesale generation costs and retail selling price? There are costs involved from generation to retail sales – generation, transmission and distribution. Services associated with generation, transmission and distribution are provided by monopoly utilities which are not under any competitive pressures hence the cost associated with these services can only go up.

By investing in clean solar power system, people can gain greater control over their energy bill while making the electric system more efficient and contributing to the environment.

Listed below are some of the benefits a rooftop solar system offer to customers and utilities.

Avoided Energy Costs – Generating electricity from rooftop solar makes it possible to buy less electricity from a utility. Because this electricity is generated locally and does not have to be transmitted hundreds of miles from a centralized power plant, energy losses that happen along the way can be avoided. This means less electricity needs to be generated by centralized power plants, and the costs of generating that electricity can be avoided.

Avoided Infrastructure Costs – By reducing demand for utility-provided electricity, the rooftop solar system cuts down on the amount of costly infrastructure necessary for generating, transmitting, and distributing electricity. Power plants need sufficient capacity to meet the electricity demand from all customers. This also requires transmission and distribution infrastructure to deliver that electricity to the customers’ homes and businesses. When electricity is produced on site from solar power system customers require less electricity from central power plants and results in less investment in generation, transmission, and distribution capacity and related costs can be reduced.

Avoided Emissions – By reducing amount of electricity needed from a centralized power plant, the rooftop solar panel also helps to avoid emissions coming from those plants.

All of these avoided costs have value in the form of environmental and electric system benefits. I can’t think of a single reason why we cannot transition to a more consumer and environment friendly solar power system to generate electricity locally.

Written by Nani Pradeepan, P.Eng.

First, what does Grid Parity mean? Grid parity means, solar PV system produce electricity for the same cost as the electricity available on a utility’s transmission and distribution “grid” from other traditional sources such as nuclear, hydro, coal, gas, oil etc. As we all know cost of electricity from other sources can only go up but properly designed and installed solar electricity cost does not change much over the years as operational cost is comparatively near zero.

Significant incentives and number of resulting solar installations have resulted in substantial prices reductions in the cost of solar power system. This means depending on the country and resources used for electricity generation, solar electricity has achieved or approaching grid parity in many parts of the world including Canada.

Solar equipment prices are three time less expensive today than it was seven years ago at the start of Ontario’s Feed in Tariff program. This has enabled electricity generation from solar closer to grid parity ahead of schedule. Other costs such as balance of system materials, labour costs have not dropped significantly but overall project cost also has dropped proportionately.

Even though hardware cost associated with solar project has come down in last seven years, soft cost (getting the incentive approvals, permit fees, LDC charges etc..) associated with solar project has gone in the other direction. It is industry’s hope that transition from Feed in Tariff program to Net-metering program will bring down these costs as well.

This drop in solar project cost has helped Ontario government to lower the incentive paid to solar power system owners and Ontario government has already decide to phase out the incentives by end of 2017. Solar system owners who secure a contract with Ontario government for selling the electricity into the grid before end of the program will receive payment for their solar electricity for 20 years from their contract start date.

Economics’ basic principle of supply and demand which has caused the significant price reduction in solar equipment price can also go other way. As more people in more countries decide to go solar, demand for solar equipment can surpass the supply and results in higher solar equipment prices. It remains to be seen what will happen to the PV equipment market. As solar industry become mature similar to Ontario government, governments around the world will phase out incentives provided for solar projects. This may keep the balance of global solar equipment supply and demand and keep solar equipment price stable.

This scenario for solar electricity reaching Grid Parity has already initiated changes in the way electricity is produced and distributed. This is just a start look out for the interesting time is a head for energy industry.

Written by Narayana Asogan, P.Eng.

In June 2016, “Energy Conservation and Long Term Energy Planning” bill (Bill 135) was passed in the Ontario Parliament, and now it is a Law. Electricity Act 1998, Green Energy Act 2009, Ontario Energy Board Act 1998 are affected by Bill 135.

Similar laws are in practice in Several US states, Europe, Australia for many years now, encouraging buildings to be more energy efficient, reduce waste of energy and water. Ontario is the first Canadian Province to implement reporting of Energy and water use encouraging large buildings to be more energy efficient.

Who are affected by this Law?

Energy and water reporting rules are to be developed by a Public Agency and applicable to Commercial, Industrial and Multi-Unit Residential Buildings (MURBs). Owners will be mandated to benchmark energy, water usage and Green House Gas (GHG) emission and provide details to Ministry of Energy.

The very first step in any long term improvement plan is Bench marking. Benchmarking is the practice of comparing the performance of an object to its peers and or established standards. It also helps to monitor the performance of the object over time and relative to similar objects.

Timeline for reporting:

Commercial/Industrial – 250,000 Sq Ft and above – July 2017

Commercial/Industrial – 100,000 Sq Ft and above, MURB – 100,000 Sq Ft and above – July 2018

Commercial/ Industrial – 50,000 Sq Ft and above, MURB – 50,000 Sq Ft and above – July 2019

Reporting of electricity, gas, oil, GHG, water consumption will be required.

Many jurisdictions who adopted energy benchmarking had shown energy and water (thus money) savings of around 10%.

Portfolio Manager developed by Natural Resources Canada with Canadian Data is recommended for Benchmarking and energy use studies and reporting.

Benchmarking and tracking energy usage coupled with good audit methods would save energy, improve energy usage intensity, GHG emission. Energy audit will guide in long term energy use planning of the building / operations.

Energy Star Score

Energy Star score is measured on a scale of 1 to 100 and involves around 150 metrics. Basic property information, energy use information, number of rooms, Heating/cooling Degree Days (HDD/CDD) etc are some of the information required. Once the required information is entered into Portfolio Manager, the buildings Energy Star Score could be obtained. Larger the number, more energy efficient is the building. Lower numbers indicate that there is a good potential for improvement.

In multi building management situation, benchmarking all the buildings will show which building requires early attention for improvements etc.

Who can do this task of data collection, analysis and reporting?

Generally anyone could do this. However the busy Building operators may not get the time to record relevant data without scarifying normal maintenance duties. In many building operations, maintenance is delayed or overlooked due to various reasons and the building and equipment may be already in poor state, resulting in maintenance situation to more costly replacement situation.

Third Party Consultants

A third party consultant (like New Dawn Energy Solutions) with specific task of such data collection and study would be beneficial to the building owners under these conditions as the legal requirements of energy and water reporting and benchmarking could be done more professionally.

As the time is short and initial data collection and assembly task would have various snags, it would be advisable to start this process early.

Also energy saving project funding including Audit funding are available from Utility providers.