Cre8-ing Electricity: Results from 1.5 years of Solar

So far, I've shared how we decided to invest in a Photovoltaic Solar System and how the installation went.  Many people ask me how the system is performing and how it affects us on a day-to-day basis.  Let me start with the easy stuff...

How Does Solar Affect Us on a Day-to-Day Basis?
Not at all.  In fact, we could just forget about this until our electric bill comes and it is lower than expected (if I didn't obsessively check the performance on a daily basis).  In our installation, the solar panels are only visible from the back yard, so we don't even look a them.  There is no change to the way the electric system works within our house.

How Did We Prepare (Reducing Electricity Usage)?
Before we went ahead and invested in this system, we took many steps to reduce the electric usage in our home.  Some of the biggest impact items were: using a programmable thermostat to lower the usage of AC/Heat Pump, add weather stripping, and lower the temperature on our hot water heater.  Some other items are:

• put vampire energy hogs (such s the cable box) on a timer, 
• not using dry cycle on dishwasher, 
• switch to CF/LED lighting
• and washing clothes in cool water.

How Much Do We Produce?
Yeah, this is where I get to show my graph.  I am a geek for Excel!  There is a lot of information in this graph.  The bars represent our total electric usage each month.  The "green" section of the bar shows the amount each month that our solar generates.  The "red" section of the bar shows the amount of electricity that we use from BGE.  The line on the graph shows the percentage of our total usage that comes from solar each month.

What Affects Production the Most?
The biggest barrier to production is 2 feet of snow covering the panels!  In fact, the only times we have had zero production is when the panels are covered with snow.  The other factors that affect this are the season (number of hours of daylight), how cloudy the sky is, and the temperature (solar panels are more efficient in cool weather rather than in very hot weather). 
 
What Percent of Our Electric Usage Comes From Solar?
Here's another (far more simplistic) graph.  BGE is our electric company.  We have no gas in our area, so all of our heating and cooking needs are met by electric.  To date, about 46% of our electric usage comes form our solar system.  When we first looked into this, I was very set on having a system that provided 100% of our needs.  After evaluating the investment, it was just not feasible for us.  Also, there was not enough room on our roof to support this.  If you look at the first graph, you can see how this percentage varies over time.  In the spring and early summer, almost all of our energy can be supplied by solar.  In the winter, it is a very small percentage.  This is not just because we generate less electricity in the winter, but because we tend to use the heat in the winter a lot more than we use the AC in the summer.

What Kinds of Issues Have We Had?
I hate to say this, because I don't want to jinx it, but we have not had any issues so far.  I am hoping that keeps up because maintenance expenses would really delay our return on investment (ROI) timeline.

What is the Return on Investment (ROI)?
Based on the tax incentives we have seen so far and based on what we can expect to save in electiricity costs in the future, our system should pay itself off by 2015.  We should break even within 5.5 years.  After that point, all that annual savings  is just money in our pocket (or in 529 plans as the case may be).  I was willing to pursue this with a 10 year ROI, so I am very pleased that it looks like it will come in under 6 years.

How Has This Changed Our Electric Usage?
I was really hoping that once we had the system installed we would continue to cut our electric usage (motivated by the desire to see that meter run backwards).  Unfortunately, this has not been the case.  Our usage has  been creeping upwards.  With only 1.5 years of data to look at, it is hard to say if this is because of the extreme weather we have been having (extremely hot and extremely cold) or just because we have become lethargic about reducing our usage.  Time and data will tell!

Cre8-ing Electricity: Our Solar Installation

In August of 2009, after we had taken efforts to reduce our electricity consumption and done a lengthy analysis on the feasibility of acquiring a Photovoltaic Solar System, we had a 7.7 kW Solar Electric System installed on our roof by a local mid-Atlantic company called Standard Solar. 

We were giddy with excitement the day of the installation.  The truck pulled up, the workers unloaded all the materials and gear and they got right to work up on the roof.

Some of the Panels anxiously waiting on the deck to be installed

The Specs

Size: 7.7kW Solar Electric System
Panels: 44 Suntech 175 Watt solar modules.

Type of PV Cells: Crystalline
Monitoring: Sunny Webbox.

The Installation
Overall, the installation was completed in two days.  The process was very painless for us - not so much for the installers being up on the roof in 95 degree weather!!  But, I did my best to keep them hydrated.

The installation involved putting the mountings on the roof to securely hold the panels, installing the panels, installing the inverter, tying into our electrical system, and upgrading the meter to a digital meter which can run forwards and backwards.

Our New Meter

Wiring through Attic to Inverter

Laying the Groudwork to Secure the Panels

Installing the Last of the Panels

It was about 2 weeks between when our system installation was completed and when the electric company approved our Interconnection Application so that the system could be tied into the grid.  Rather than having a battery backup, our system is tied into the electric grid.  This means when we are producing less than we use, we pull electricity from the grid and our meter runs forward.  If we are producing more than we use, we push electricity back to the grid and our meter runs backwards.  Being tied into the grid means that when there is a power outage in our area, we still experience that power outage.  We are okay with that, because it doesn't happen too often for us.  Standard Solar has a great little video on how the Solar System works in this setup.

So far, after a year and a half, everything has been working just as expected.  We have not had any issues or problems so far.  In the next Solar Post, I'll tell you how we track the performance of the system and how it has been doing with all this extreme temperature in the Mid-Atlantic over the past two year.

How about you?  Do you have a solar system?  Are you considering alternative sources of energy?

Cre8 Your Own Energy: Documenting our Solar Project

Okay, so I am not building my own solar panels or anything, but the stars aligned for us this year and we are able to get solar panels on our home. I hope to document that process here a little bit.

Step 1 - Reduce Energy Usage
Of course the process started over a year ago for us. It started with an awareness of how much energy we were using and wasting. We only have electric available in our neighborhood - and boy, were we using more than our share! In the winter, our bills $400-$500+. So, being the geeky engineer-types that we are in my household, we immediately started tracking our usage and started an aggressive campaign to reduce our electric usage. We turned down our heat, turned up our AC, got rid of our "vampires", switched to CFLs, turned the lights off, among many other little energy saving changes. The results were dramatic! I would say we save about $1700/yr over if we had not changed our behavior. This graph is what we've been using to track our usage over time.



Step 2 - Cost/Benefit Analysis
So once we reduced our usage, we looked at the costs and benefits of installing the solar panels on our home. The up-front costs are very high, approximately $60K for the size system we are getting. Luckily, this year there are many state and federal grants and rebates that end up cutting the cost in half to about $30K. We are using a local company called Standard Solar that will take care of all the paperwork and permits for us. Now, we will expect $1200 cost savings every year on our energy bill. In addition, the energy company will pay us a credit for producing clean energy (like a carbon offset price). This system should (theoretically) also increase the value of our home by about $30K. The financial Return on Investment for us (minus the increase in home value) is about 11 years assuming energy costs stay the same. Now, if energy costs rise, our ROI will come much sooner.

That is just the financial benefit. There are also benefits that are not financial. One is knowing that we are not burning through as much natural resources to create our energy. Another is emergency preparedness. If our electric service became rationed or more unreliable, we have a good solid backup. Also, it is a great learning experience for us and the kids. So, overall, it was a go for me and my husband.

Step 3 - Evaluation, Planning, Permits, and Design
Now, this was the easy part for us because the Solar Company does all this work for us. Our solar rep came out and took a bunch of measurements and pictures of the house. They tested the sun exposure and determined that we would have 89% efficiency with the panels. The panels will be mounted on the east-facing back of our roof, so you won't even see them from the street. An engineer at the company then made up a bunch of technical design drawings for us to review and approve.


Now that the design is complete and the permits are pulled and the paperwork is filed, we are ready for our installation. That is yet to happen. I'll let you know how it goes...