Project Template

BACK TO 2011 SPRING

Project Summary

We built a renewable energy to low voltage DC electrical converter, to help provide electricity to those living off the grid in the MENA region. Our device consisted of three main interconnected modules, an input module, a power-management module, and an output module. The input module allowed the user to charge the device with power from a solar panel or directly from the wall. We also built a priority encoding circuit that picks between multiply from of inputs, if they more inputs were to be added in the future. The power-management system contains a battery, a custom battery power-level meter, and 12V and 5V voltage regulators. The output module contained two 5V USB ports, two 12V car lighter ports, and a set of multi-functional LEDs.

Intro

The Problem

Overview

Developing countries have a rapidly growing usage rate for low voltage DC devices such as cell phones, lighting, and portable heating and cooling appliances; but given the relatively high poverty rate in these, many people cannot afford expensive electricity bills. Developing nations, however, have an abundant amount of renewable energy resources, and the technology needed to harness that energy is already in existence. Our goal in this project is to design and build an affordable user-friendly household product that utilizes renewable energy resources to fulfill the increasing demand for low-voltage-powered appliances. The geographical focus for our product is going to be the Middle East and North Africa (MENA), with an extensive pilot program in Jordan.

Solar Energy

There are numerous sources of renewable energy, ranging from wind power to trash. The most abundant, however, and most easily accessible in the MENA region is – by far – solar energy.

Concerns about CO₂ emissions and future energy supplies have led to a recent surge of interest in solar power, with new plants now being planned or built around the world. The statistics are quite startling. Every year, each square kilometer of hot desert receives solar energy equivalent to 1.5 million barrels of oil. Multiplying by the area of deserts worldwide, this is several hundred times the entire current energy consumption of the world. It has been calculated that, if it was covered with solar power plants, an area of hot desert of about 254km x 254km (shown below) comprising less than 1% of the total area of such deserts, would produce as much electricity as is currently consumed by the whole world. An area measuring 110km x 110km, a small fraction of the area of desert in North Africa and the Middle East, would produce the same amount of electricity as the European Union consumed in 2004. This is illustrated neatly by the diagram below.

MENA Regional Challenges

In most regions, extensive power grids deliver electricity to households and firms. However, in some remote communities of developing nations (usually rural or desert) there are still significant areas that aren’t connected to a public power grid and do not have access to a power source. The following map illustrates Africa’s existing power grid. From this image it can be seen that large portions of northern Africa do not have access to a power source. Coincidentally, this area is the same region that has an abundance of solar energy as was illustrated in the previous figure. The problem is that there is no existing device or micro-grid to connect solar power to households in a convenient manner.

The majority of electronic devices in use today operate on low voltage DC current. Low voltage DC can be used to power lights, heaters, coolers, cell phones and various other small electronics. One of the most common uses of low voltage outlets is wireless cell phones. In the MENA region, the wireless telecommunications industry has started to boom. Since 2007 the number of wireless subscribers has nearly doubled. With such a vast increase in demand for cell phones, there are many cellular users who do not have access to the means to easily charge their phones. GSMA published a report that mentioned 500 million African mobile phone users don't have grid access.

Another problem that was previously touched upon is the inability of many poor households to afford expensive electricity bills. An investment in an affordable renewable energy to electrical energy converter will certainly help appease that problem and provide basic necessities to them such as indoor lighting, heating, cooking, and cooling.

Jordan Challenges

                Jordan has almost no indigenous energy resources and energy imports account for nearly 10% of GDP. It imports 96% of its energy and is considered one of the world’s 10 poorest counties in water resources. Due to economic growth and increasing population, energy demand is expected to increase by at least 50% over the next 20 years. Therefore, increased access to reasonably priced indigenous energy sources is crucial to successful economic reform and the reduction of Jordan's dependence on foreign sources of energy. The Government of Jordan is committed to increasing the share of indigenous energy resources, including all renewables and oil shale, from their current level of about 0.5% of total electricity generation capacity to around 10% of total installed capacity.
     Despite Jordan being very poor in terms of indigenous energy sources, it is very rich in solar energy. The southern part of the country is particularly sunny, providing excellent radiation indices and making the country one of the world’s ideal places for solar energy production. In fact, Jordan’s solar potential has been recognized and is recently being tapped into by a consortium of Jordanian and international organizations who intend on building a multimillion Photovoltaic power plant in the south by 2012. The plant is estimated to have a capacity of 100 megawatt of electricity generated from a mere 2000 square km patch of desert, according to a leading member in the consortium.
     All of this serves as solid evidence to the tremendous solar potential in Jordan. We come in to provide affordable renewable-to-electrical energy household converters to people who live far from the public grid, and to the socioeconomically disadvantaged who need more electricity but do not have the means to pay for it.

Proposed Solution

Theory

The use of photovoltaic (PV) energy in buildings is usually associated with a connection to the public electricity grid. The grid connection requires a conversion from direct current (DC) to alternating current (AC). This conversion enables both the use of standard AC household equipment and a connection to the public electricity grid.

Many household appliances, however, function internally on DC. Within the AC equipment an alternating voltage of about 230 V is transformed to a (low) DC voltage, for example 12 V. Utilizing PV energy in this way involves two energy conversions with inherent energy losses. It is reasonable therefore to assume that these losses could be avoided by introducing a DC (low-voltage) grid.

Technology

• Photovoltaic cells to capture energy
• Alternator for mechanical charging
• 5V USB 3.0 output ports
• 12V Car lighter output ports
• Power Transformer
• Voltage regulator
• Various circuitry to divide and delegate power

Design

Requirements:

• Device must meet all demands pointed out in “Design Objectives” and “Technology”
• Device must be cost efficient < $500
• Device must be light weight and portable< 30 lbs.
• Device should be sturdy and easy to handle.
• Smooth Surfaces
• A Handle
• Device must me modular and ready for additions
• More Power output options (i.e. combine two modules for greater voltage)
• Different output forms (i.e. screw terminals, general outlets)
• More methods of battery charging (i.e. alternator for wind, or bike charging)
• Device must be intuitive and easy to use
• Inputs and output connections must be intuitive. 

Requirements

• Device that will collect and store solar energy.
• Device will contain a mini-grid to deliver low voltage DC to many output forms.
• Device will be user-friendly, sturdy, and low-maintenance.
• Device will have voltage regulation to ensure power levels are safe and have constant output values.
• Device will come in modular form so that future attachments such as methods of charging and more outputs can be added.
• Device will be able to tie into grid to supplement available power.

First Prototype

Second Prototype

Final Results

FINAL List of Requirements

Required 

• Device will be light weight and portable< 30 lbs (not including renewable energy attatchments)
• Device will utilize a lead acid deep cycle battery to store electrical charge.
• Device will be able to charge using at least one form of renewable energy (priority will be given to solar energy, due to regional focus of choice)
• Device will be able to charge straight from the standard high-voltage AC power sockets of residential homes, regardless of which country it is used in
• Device will take in an input of 110v-240v versus only 240v or 110v
• Device will contain a mini-grid to deliver low voltage DC to more than one output of varying forms. Specifically, the device will have:
• three 5V USB 3.0 output ports
• two 12V car lighter output ports
• Device will be user-friendly, sturdy, and aethsetic
• Device will have a voltage regulation system to ensure power levels are safe and have constant output values
• Device will come in a modular form so that future attachments such as methods of charging and more outputs can be added
• Device will utilize creative puns to come with an appropriate name involving both electricity and super-heros
• Device will be intuitive and easy to use
• Inputs and output connections will be intuitive. 

Optional (Extra Credit!)

• Device will contain a modular add-on to put back excess generated electricity back into the grid, safely.
• Device will implement priority encoding that chooses between several forms of energy input. (e.g. solar and high-voltage AC).

New Electrical Engineering Skills Gained from ENGN1000

We learned many useful skills that we are eager to take with us and implement in other engineering classes, future jobs, and even in entrepreneurial endeavours. Some of these skills are listed below:

Hands-on

- Working with the PCB and soldering the mini-components on it

- Machine shop for mechanical structure and enclosures

- Gained knowledge and familiarity the digikey catalogue

- soldering

- PCB software

Conceptual & Applied

- SEPIC converters

- Buck/Boost converters

- DC/DC voltage regulators (linear vs. nonlinear)

- AC/DC voltage regulators (offline switching regulator)

- Photovoltaic cells and photovoltaic modules

- Deep Cycle Batteries (lead acid vs. gel)

- Priority encoding (we were introduced to this concept indirectly in ENGN1630, but ENGN1000 gave us the chance to apply this knowledge to a real project)

- Grid-tie inverters

-wire gauge and current

-the purpose of fuses