Fig 1: Three phase electricity monitor

Fig 2: Back side of the meter

Fig 3: Back side of the meter

Fig 4: Front side of de meter

Introduction

Electricity meters exist in various types and sizes. This meter in particular is a three phase monitor intended to measure various electrical parameters on three phases simultaneously. This meter is for industrial use as wel for houses which have a three phase electricity network.
This outstanding three phase electricity monitor has a large display, programmable parameters for alarm levels, Current transformer ratios, Voltage ratios and much more.

Applications

This meter is useful for any one connected to the electricity grid who want to know more about their electricity consumption and quality of electricity. The meter can al be used for system installer who want to upgrade their products with extra information regarding electricity consumption. Some examples of applications are:

• Three phase Motors
• Air Conditioning installations
• factory plants
• Hotels
• Shops

Services

We offer the following services:

• Sales of power meters
• Installation and integration of power meters
• Instrument panels with meters, switches, fuses, and outlets
• Software development for specific power meter functions.
• Presentation and demonstration of digital meters in general

How to order

This meter is available. You can order it by activating the following email address link, fill in the form and send this email to: info@holamex.nl , the form is all predefined. You can also order by activating the “comment” button at the top of this page and send a request with the message that you want to buy this meter and fill in the contact details field.

Costs of the meter

Fig 1 : El medidor tal como es.

Fig 2 : El medidor desde un lado.

Fig 3 : El paquete

Introducción.

Si lo que necesitas es conocer la cantidad de electricidad que es utilizada, o qué tan estable es su red de electricidad, este medidor es la solución. Con este medidor inteligente no tendrá más preguntas acerca de qué y cuánto electricidad que consume.
Este medidor es inteligente porque le dice cuatro cosas por el precio de uno. Le dice su:

• Uso de electricidad (kWh).
• Energía eléctrica (W).
• Voltaje (V).
• Corriente (A).

Hecho por HOLaMEX y “culumus de Ideas”.

TEste producto ha sido desarrollado en cooperación con HolaMex y Culumus. Holamex es una empresa holandesa-mexicana especializada en soluciones inteligentes de energía para los hogares y la industria. Cumulus es un buró de diseño gráfico ubicado en Querétaro (El Pueblito) y es responsable del estilismo producto.

Ambas compañías colaboraron y desarrollaron un producto que da a la gente en México más control sobre su gasto de electricidad. En donde todos salen ganandoLo que obtiene y que es el costo.

What you get and what it Costs.

Fig 1 : The meter as it is.

Fig 2 : The meter from a side.

Fig 3 : The package

Introduction.

If you need to know how much electricity you use or how stable your electricity network is this meter is the solution. With this smart meter you have no more questions about what and how much electricity you use.

This meter is smart because it tells you four things all at ones for the price of one. It tells you your:

• Electricity use (KWh).
• Electric Power(W).
• Voltage(V).
• Current(A).

Made by HOLaMEX and “Culumus de Ideas”.

This product is developed in cooperation with HolaMex and Cumulus. Holamex is a Dutch-Mexican company specialized in smart energy solutions for homes and industry. Cumulus is a graphic design buro located in Queretaro (El Pueblito) and is responsible for product styling.

Both companies have put hands together and developed a product which gives people in Mexico more control over their electricity spending’s. This makes it a win win for everybody.

What you get and what it Costs.

This meter is for sale in limited volumes for the price of $750 mexican pesos.
for this price you get :

• The meter
• An installation and user manual.
• Installation materials.

No extra materials are needed to install other than a drill and a screwdriver. Everything is packed in a strong carton box.

How to order.

This meter is available in limited volumes. You can order it by sending an email to: info@holamex.nl using your email program outlook or something else or by activating the “comment” button at the top of this page and send a request with the message to buy a meter.

Solar panels are sold in powers of 250…310Watt but what do they offer in real operational conditions. You can also say what can we expect of our solar installations in real life. Solar is applied in two basic configurations and each of these have their own losses. The two most know configurations are:

Fig 1 : Typical roof installation of a GT Solar installation

• Grid Tied installations (GT)
• Off The Grid Installations(OG).

The losses in these two configurations are divided in three groups. These groups are:

GT installations:

• PV Panel loss due to cell temperature.
• Loss due to DC/AC conversion or inverter losses.
• Loss due to transport, Soiling, shading, panel aging and more.

OG installations:

• PV Panel loss due to cell temperature.
• Loss due to DC/AC conversion or inverter losses & battery storage and discharge
• Loss due to transport, Soiling, shading, panel aging and more .

Fig 2 : Effect of temperature on cell performance

As you can see the difference between the two configurations is the loss due to the use of battery storage.

The next post I will describe the losses for these two applications. All losses can be calculated using formulas. Were possible it is explained . The calculations for panel loss is left out of the scope of this paper.

PV Panel loss due to cell temperature:

A panels is constructed with cells in a array and each cell has an efficiency that goes down with the temperature going up. How much it goes down per °C is determent by a PV power Temperature Coefficient TCpmax which is around 0.47%/°C
The Cell temperature of a panel goes up as soon it receives Solar radiation in order to produce electricity. Temperatures of 55°C at 1000Watt/m2 irradiation and higher are not unusual. This means under these conditions our panel performance is not 100% as it is sold for but has reduced to 86% (sorry it is not just multiplying Temp x TCpmax). The operational panel performance at 1000watt/m2 irradiation is around 86% of the performance its sold for.

Loss due to DC/AC conversion or inverter losses:

Fig 3 : Open DCAC inverter open model explained.

An DC/AC inverter exist out of two stages. Stage one is a boost stage that pumps up the panel voltage of say 40V to the needed AC line RMS voltage multiplied by the root or 2 which is 1.41. That product is the peak voltage needed to produce an AC signal with an RMS equal to your line RMS value. In Europe this voltage is 230Volt (Peak=325V) and in the Americas it is around 120V Peak=170V.

The second stage in a DC/AC inverter is what is called a “H MOSFET bridge” that inverts the boosted signal from the first stage in to a Sine wave Pulse Width Modulated (S-PWM) signal which goes though a passive LC filter. Belief it or not but a S-PWM signal at the input of a LC filter make a 230/50hz or 120V/60Hz sine wave coming out, it’s like magic.

These two stages count for a loss between 90…97%. For this exercise we use 95%, most DC/AC inverters have figures like this. keep in mind  but only for their peak efficiencies, the average is often lower.

Loss due to battery storage and discharge.

Fig 4 : Voltage efficiency of a lead acid battery

To charge a battery requires more energy than you can get out of it during the discharge stage. The quotient of the output and input energy is called the efficiency of a battery. Two effects influence this efficiency and they are called the coulomb and voltage efficiency.

The current or charge (I*t=C)that you put in a battery is not the same charge that you can get out of it. The quotient of the two is called coulomb efficiency.

The voltage needed to charge a battery is not the same as the voltage you get out of a battery during discharge. The quotient of the discharge and charge voltages is called the voltage efficiency.

The product of voltage and coulomb efficiency is called the efficiency of a battery. A lead acid battery has an efficiency of 80% a Li-Ion battery has an efficiency of 99%.

System losses:

The list of variables that may influence the efficiency of solar installations other then what is discussed before is called the system losses. The system efficiency is also influenced by the following factors:

All these losses are estimated in percentage of their effect on the system performance. If they are considered zero they are not mentioned. The following degradation in performance can be expected is as:

Over all Efficiency

Now we have made and estimations of all losses in a GT or OG solar panel system we can have a look at what the total outcome is. Lets calculate the overall system efficiency and see why your seller is never telling you this. This overall system efficiency is calculated as follows. The Panel operational efficiency multiplied by the Inverter efficiency multiplied by the system efficiency.

For GTI and OGI we come out on:

These are the real system efficiencies that you have on your roof in the first year. They might be a little different but not that much. Meaning an GT installation like 10x 250w panels can produce on a nice summer day with 1000Watt/M2 of irradiation not 2500Watt but something closer to 1850Watt.
With lower irradiation levels the panels get less hot and there for the panel efficiency will go up a little. At the same time less irradiation also means less incoming energy to covert. The total power production with lower irradiation will always be lower.

Every year the system gets older until the 25 Year life time of the panel system. The efficiencies after 25 year will have dropped to :

An other side effect of this operational analysis is the conclusion that most system in location of 45° latitude or higher will have inverters which are to big for the panels. At these latitude level the sun with not often produce 1000Watt/2m irradiation. So a 300 Watt panel will maximum produce most of the time below 225 Watt of power. This means a inverter of the size of 225Watt  is sufficient for panels of 300Watt instead of a 300Watt inverter. That saves some money since the inverters are 30% of the installation cost.

If you compare the overall system efficiencies with the amount of sunlight coming in then the overall efficiency of available energy compared with actual energy used is around 10.. 12%. We still have some work to do be for we can actually use what the sun is offering us.

I hope you have given you a better idea about what your solar installation is actually doing at your roof and what we need to do to get the numbers up. Happy renewables

Regards
Oscar Goos

Introduction

The ATmega328 PLC is a credit card controller packed with many useful functions. It is light weight, consumes low power, has a DIN rail case, build in display, backup power and is scalable. With this PLC you can build and control anything you like. Compared with other PLC’s there is no need for special power supplies, or other interface modules. Practically any sensor from any manufacturer can be connected. On top of all this it is cheap compared with others PLC’s in the market.

The picture below shows the PLC as monitor and measuring device of the electricity grid. This application can activate generators and backups at times when the CFE has blackouts. ( Grid values are zero because the photo is for demonstration purpose).

The inside

The PCB is a high quality double layer made of glass fibre, 1.5mm thick, routing is done with 10mil traces. The PCB measures 100×68 mm has 85 components, the enclosure measures roughly 107x88x60 mm.

Below an image of the PCB layout and the various functions and interfaces.

Interested to buy : send a message

The idea behind it

This PLC was developed for different reasons. One reason was to generate a flexible control platform with a display integrated to control any process you like. A second reason was to offer a complete integrated PLC solution to any one like students professionals and engineers. With this PLC you can focus on your job instead of being busy how to assemble and install a PLC controller.

The basic idea regarding the specifications for the PLC was:

• It had to be small in size with a low power consumption
• Should run from solar panel and or standard Lithium or lead acid batteries.
• It should have build in AC power drivers.
• Had to be expandable or scalable.
• Standardized Interfaces and there for sensor manufacturer independent.
• Equipped with a large display
• Memory to store statistic measurements.

Applications:

This controller platform has a number of applications. Some are available and some are in a concept phase of development. Holamex works on the following applications.

• Photo voltaic energy monitor
• Smart solar collector differential thermostat
• Battery heath monitor and charger.
• Swimming pool controller with automated pool and garden light timer
• Load control for factories with high energy demand.
• Light lux meter.
• Flow meter
• High way traffic density counter.
• Smart Solar light post monitor and battery maintenance.
• CFE grid monitor with backup switch functionality.
• Air pollution monitor.

Functions:

The following functions are implemented

• Central controller, ATmega328
• RTC, Real Time Clock with high accuracy, DS3231,
• Non volatile RAM, AT24C256, 64KB
• RS485 half duplex bus, MAX485
• ADC external reference, multi turn pot meter
• Temperature sensors, DS3231, ATmega328
• Push buttons.
• LCD Display 4×20.
• External Terminal port / PC interface

Ports on the module

The ports on the PLC allows connecting external sensors or measurement modules. Some of the ports provide beside the GPIO signals also the necessary power to feed the external modules or sensors. The ports are implemented with 3.81 mm pitch screw terminals. The following ports are available:

Fig 1 : PLC LCD Display 20×4

Introduction

Programmable Logic Controllers (PLC) are small computers which perform a number of logic functions in order to process inputs and control outputs. They are used in the industry.

PLC’s normal exist out of a power supply, a central logic control unit and interface modules. they fit in DIN rail cabinets.  They are often programmed using specific Graphic oriented software. 

Fig 2 : PLC PCB

My goal was to develop a PLC existing out of one units having all what most industrial processes need. No extra modules and most interfaces you need. there are no limitations on functionality because it is programmed in “C” language.

This PLC has all the interfaces as described in the table below. The general purpose ports, TS485 and I2C ports are implemented as four wire ports. Each four wire port has two protected micro controller IO lines and a selectable 5Vdc or 12Vdc power.

The photos on the right shows the PCB Display of the PLC. The unit has the following interfaces

Interfaces :

The functions implemented  on this PLC are the following.

Functions :

Fig 3 : PLC+Displ

The dimensions and other physical characteristics of this PLC are:

Physical Characteristics:

Fig 3 : PLC+Displ

The schematics for this PLC was entered in NI-Multi-sim and layout of the PCB was done using NI-Ultiboard. I want to say thanks to national instruments for their support.

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Fig 1 :Panic button and GPS tracer.

Fig 2 :Google maps at mobile.

Fig 3 :Panic button on the Tracer