Monday, December 30, 2013

Solar Project Update #1

Ok for the first update, I'll share some photos of what I have so far on the project.

500W Grid tie inverter
The grid tie inverter is the first device I acquired from an online local seller. Acquired it last Dec 14. So far it works during testing by connecting it to a car battery while the engine is running. I was only able to produce 210W tops, not sure what is keeping it from producing more power. Maybe it's because the battery is small or the connecting wires aren't thick enough but it's enough to confirm the device is functional. How did I know it reached 210W? I used a watt meter and I'll introduce it later.

500W grid tie inverter specs:
DC Maximum Input Power - 600W
DC maximum voltage - VpvDC30.2VDC
DC voltage range - Vpv 10.5V~28VDC
Maximum output power factor - 99%
Maximum input current - 30A
AC output power - 500W
AC maximum output power - 500W
Anti-voltage protection - Fuse
AC standard voltage range - 180~260VAC
AC frequency range - 50HZ~60HZ

One thing I should point out that grid tie inverters (GTI henceforth) does not work when there is no grid power. When there is a power outage on the grid, the GTI automatically turns off, this is called anti-islanding and it's meant as protection to the person servicing the electrical system.

Tools

During the course of the project, I will need to use tools. Some of the tools I already have and some needs to be purchased. The cost of these tools will not be taken into account when computing for the return of investment (ROI henceforth) as tools have their own ROI each time they are used for many projects.

One of the tools which I already have is the watt meter:
Watt meter 
This watt meter was bought a few years ago which I used to monitor power consumption of various appliances including the air conditioner. It can measure wattage up to 3500W. It can store data in an sdcard and can graph the energy usage using a software included with the device. However, I won't be using this once the GTI goes into normal operation since this device is sensitive to power surges. I had this serviced once due to power surges. I bought a cheaper watt meter instead for this project:
Cheaper watt meter
Another must-have tool is the clamp meter. During my recent visit to Raon, I found a very cheap clamp meter. Since I badly needed a clamp meter to verify the GTI is indeed slowing our power consumption from the grid, I bought one:
Cheap clamp meter
This clamp meter only works in measuring AC current. It cannot measure DC current via the clamps and I will also need a clamp meter which can read DC current to measure the solar panels output current. I'm currently on the lookout for a better clamp meter. 

Last but not the least must-have tool is my digital multi-meter (DMM) which I bought many years back:
good old DMM

Back on the project...

On Dec 27, the solar panels have arrived:
100W solar panel
This is one of the six panels I ordered online (it's cheaper and better quality from Raon varieties), note my DMM on the upper left of the photo, I used my DMM to see that the panel is producing up to 24V.
The panels are to be installed on our house roof so I asked the help of my dad for the metal works. Initially, I plan to put up aluminum mounting but after consulting with dad, he and I decided to go with iron mounting.

Roof status as of Dec 27
The solar panels will be mounted on an elevated rail instead of laying flat against the roof. This will help on cooling the solar panels as heat reduces its power output. 

On Dec 28, while the roof mount was still under construction, I tested one solar panel just laying flat on the roof and connected it on the GTI and measured the output using the watt meter and here are the data I got:

8:45am - 56W
10:13am - 75W
around 12nn - 82W
around 1pm - 66W
around 2pm - 54W
around 3pm - 45W

Total energy produced  - 249WHrs

The measured Watts is only the peak power it shown at the time, power fluctuates constantly specially when there's a cloud passing between the panels and the sun. After 3pm, I'm already getting shadows from our mango tree and the output drops and causing the GTI to recycle and cannot produce more than 20W anymore. Please note that for each solar panel, there should be no shadow casted on any of the cells, if there's one cell that is shaded, the entire panel output will drop to near zero, this is because the cells are connected in series, the solar panel with only be as strong as its weakest cell. The energy produced for the whole day is much lower than I expected, this is due to the weather on that day which is only partly cloudy. This causes the GTI to recycle when the sun gets blocked by clouds many times during the day.

On Dec 29 Sunday, I have work duties so I was not able to take photos of the roof mountings but my dad continued with the metal works and by the end of the day, 5 solar panels have been mounted as well as the wiring conduit through the roof.

Tomorrow we shall work with the wiring from the solar panel to the attic in which a part of it will become the power control room.


Saturday, December 21, 2013

New project

Hi,

It's been a while since my last blog. On my last project, the Raspberry Pi project, I've made a total of 3 RPi devices. The third was only completed recently and it's for our media center for the living room. My 4th RPi is still stored for future use, as a backup or maybe a development unit.

Moving on, with the current power rate hikes rising to record level and the government's implementation of net metering. I've decided to invest and setup my own solar power project.

typical roof mounted solar panel

Last week I've bought the first device, a 500 Watts grid tie inverter. What this does is produce energy and fed it directly to the power grid  (Meralco). No need to purchase batteries to store energy. Example, if at daytime we are consuming 600 Watts of power and the grid tie inverter is producing say 400W, then we will only consume 200W from the power grid.