Energy management is a crucial topic for companies, as prices can be a concern and bills may increase unexpectedly. It is important to manage energy usage efficiently to avoid unnecessary expenses, and renewable energies offer a potential solution. We all may have come to the same conclussion at some point in time: “we need a change…”. However, it can be difficult to know where to begin such an important move.
Today, we will discuss a real solar panel installation project for a small company. Investing a moment of your time in research is simple and important, as it will result in significant savings!
For the readibility of this post, we will not dive into specific and technical details.
THEORY
Electricity is such a wide area of knowledge, which makes it essential to get to know it (at least the roots), before getting into the analysis stage. It may sounds stupid, but it is typical to see companies jumping into it without any prior knowledge about their reality. Therefore, we will first stick to theory and legal requierements before doing our practical research.
It is important to note that the government has legal control over everything, and all information is open-sourced and available to the public (the following website contains all the necessary information).
* We will talk about legal concepts, so take into account it only applies to Spain and similar countries.
First thing is to understand what type of electricity contract we have:
| Contract | Power | Voltage |
| 2.0TD | Pc <= 15 Kw | V <= 1 KV |
| 3.0TD | Pc > 15 Kw | V <= 1 KV |
| 6.1TD | 1 KV < V <= 30 KV | |
| 6.2TD | 30 KV < V <= 72.5 KV | |
| 6.3TD | 72.5 KV < V <= 145 KV | |
| 6.4TD | V > 145 KV |
Legally, in Spain, companies are differentiated based on two main electric variables: power (measured in kW) and voltage (measured in V). This information is displayed on your bills and determines how your invoices are calculated.
As for our specific case, we will work with 3.0TD contract, which belongs to a small company, where electric invoice will be monthly measured according to six time periods:
Where, as you can see by the color legend, periods are invoiced according to the month we are in.
This theory is based on the average behavior of companies. Periods 1 and 2 are the most expensive, as they coincide with the months when electrical consumption is typically higher.
Prices for each of these periods are regulated by the government, therefore we have access to it and we can do our researches whenever we feel like it.
Between all the variables that we have included in our bill, the most important one for our current research is the Active power, the one which measures the Kilowatts per hour (Kwh), or, in other words, how much we consumed during the month:
Up to this point we do have all the information we need to start doing our research about a possible photovoltaic installation, as we know how much we will be charged of, and when and how it will be done.
In case you have some questions about how this calculation needs to be done, feel free to contact me!
ANALYSIS
There are two different sets of data we need to know to measure our project:
- Electricity bill: as we have said before, it is important to know how much we are currently paying, and how much we will pay in the future, in order to have something to compare against.
- Solar panels: we must measure the efficiency of our panels by calculating a production forecast for the same time period.
The question that we may be asking ourselves right now is:
How can I measure the production of something that I do not have yet? (solar panels)
The European Union provides a free tool for calculating solar production in a specific area. This allows us to research production for our company address and determine potential output.
We supposed here a installation of 50Kw, with a 15% of loss (of course you can be as specific as you want with technical details: materials, power, efficiency, angles…), but at least I recommend to enter the power installed as I did.
Up to this point, we can perform the study and check the investment’s profitability. I have created a simple Excel system that you can use to enter your data and evaluate the project’s feasibility:
Solar production forecast, given by the European Union tool (link in the image above).
The company’s solar panels may produce energy that is not immediately consumed. To optimize energy usage, it is recommended to understand the company’s schedule and determine when energy will be consumed during production phases.
Consumption forecast of the company
Savings according to solar panels reduction
Maintenance costs
Difference between savings and costs
Return of the investment
If we perform this study for a 25 years period (which is the average period the installation should be working as expected), and a investment of 50K€, we would get the following forecast:
- Breakeven point: 3.5 years. That means we will get our investment back after 3 and a half years.
- Savings: 280K€. That means we will save up to 280.000€ after 25 years of the project.
Big J
In conclusion, our research shows that this investment is worth trying. Furthermore, we will achieve significant savings.
