ENERGY WANTS & NEEDS CLASSIFICATIONS
Since 2007, Specialized Solar Systems’(SSS) experience in providing electrification to those under-served by the South African National Grid has resulted in the formulation of a set of energy supply principles within acceptable parameters of the traditional electrification paradigm.
With this experience which includes working in collaboration with universities, NGO’s, governmental and private enterprises it became evident that the targeted LSM 1-3 human energy requirements could be supplied to support an individual’s basic energy wants and needs using Low Voltage (LV) Direct Current (DC).
These principles would safeguard electrification delivery priority for disconnected rural and peri-urban informal settlement communities.
Coupled with efficient DC appliances low voltage DC electrical distribution supports impoverished consumer demographics energy wants and needs from the very basics then progresses to more comfort luxury appliances, enhancing the available options for a consumer as their energy requirements grow.
LOW VOLTAGE SOLAR Electrification DISTRIBUTION – BUILDING A BUSINESS MODEL
With the reduction of energy consumption using efficient low voltage DC appliances, a load profile can be defined in relation to a priority number (Figure 1). By using these load profiles, creating a sustainable energy supply model using photo-voltaic (PV) based energy generation hardware combined with modern storage technologies is now possible.
The daily energy generational capacity is carefully modeled throughout the year taking historic and unforeseen circumstances into account. Energy generated and stored should be used effectively by monitoring and evaluating the correct distribution between the PV generator, storage, and consumption.
Consumer contracting of individually selected bundled DC appliances with the monitoring of their energy usage allows for load profiling to balance the total supplied energy (batteries and PV) and contributes to a sustainable electrification model.
Full control of this energy distribution model enables a proficient understanding of the energy potential and how much energy can be produced and at what capital value. This is achievable by developing system intelligence with remote access, energy control, and automated billing and switching mechanisms.
These above energy balancing processes lays a foundation for the creation of a sustainable business model.
LOW VOLTAGE DC APPLIANCES
For many years Specialized Solar Systems has been creating, updating, and testing low voltage DC products for efficiencies and durability. Using a business model based on delivering on various energy demand profiles, these low voltage DC appliances are combined in different configurations to deliver on a variety of demand profiles and thereby satisfying consumer’s wants and needs.
ENERGY PROFILE = BUNDLE DC APPLIANCES = LOAD PROFILE = SYSTEM DESIGN
The combination of low voltage DC appliances results in a 24-hour load profile. The load profile can be used to form a base specification of the kWh requirements for building energy generation systems. Attractively packaged DC energy bundles are marketed to consumers that support and deliver on their energy appliances needs.
PRIORITY SOLAR MICRO GRIDS DISTRIBUTION METHODS
Solar generation and storage DC micro-grids have the potential to fill disconnected gaps in grid infrastructure. When designing low voltage DC micro-grid systems that fully power households, it is important to design systems that are reliable, modular for system growth, and require minimal maintenance.
Using low voltage direct current that complies with regularity standards supply’s energy in a range that carries a low risk of dangerous electrical shock and allows for quick training and deployment of the installation processes. Often projects make use of unskilled locals to install and maintain systems resulting in economic betterment.
Solar Towers allow for higher capacity and more intelligent devices with smart networking (ITC) features for generating and storing energy. The energy generation and storage mechanisms must consistently deliver on the total demand profile through wiring reticulation among the connected households using bundled DC appliances, different DC voltages.
For example, if a Solar Tower has a load profile for supplying 3200W over a 24 hour period, and if all the connected households make use of the same bundled DC appliance with a load profile of 200W each over a 24 hour period, the Solar Tower can then supply 16 houses with energy, daily. An advantage of using a gridded system is that not all consumers will use their maximum demand profile or use energy at the same time which allows better energy balancing (ADMD and BDMD calculations).
Equipped with the latest industrialized technology, a Solar Tower’s internal energy management hardware is all located in its tamper-proof designed tower head. Here, the system’s core intelligence continuously validates data between internal hardware configurations making it’s own management decisions based on configurations with safety features built-in. The recorded energy generation, stored energy, and consumed energy data with other data-sets is delivered with low-data overheads to cloud-based servers using a variety of connectivity protocol options for data delivery.
STANDARDS AND MANAGEMENT
Each Solar Tower is integrated into remote management platforms for system and customer management, billing, point of sales administration, consumption management, switching, and more. Solar Towers are extremely durable. They are built, set up and maintained to the highest specifications and safety standards. Using the latest technologies such as:
And conforming to the following standards:
Energy management applications access all this information and allow for key components to be remotely programmed and configured for optimal performance by solar specialists. Energy resources are carefully balanced to meet the households DC appliances load demand. Any excess energy is either distributed or stored.
A households DC appliance bundle will use a certain wattage over 24 hour cycle. The consumption is carefully monitored and reset when the cycle completes. When total usage on a load profile is exceeded over a cycle, certain actions such as notifying the consumer to lower their usage or switching the energy supply OFF then take effect automatically. Each household has a DC Meter that features short circuit protection and a configurable peak usage threshold for safety and control.
The PAYGO billing package is a rental-based payment for daily usage upfront billing structure.
The customer only pays for the duration of the daily energy supply.
PAYGO allows for varying amounts of value-driven rates to be added to a PAYGO billing package giving a customer attractive bundled options (Days versus Amount) when making payments.
It includes ON and OFF switching directly related to a bundles’ expiry date, account balance, and 24-hour load profile consumption calculation total.
The contract billing package is a rental-based monthly debiting billing package.
A value is set for the energy supplied and this value is deducted monthly on a defined day every month.
It includes ON and OFF switching directly related to the accounts balance on the monthly debit date and 24-hour load profile consumption calculation total.
The package includes a reconnection value and if selected, will charge the account with the value if switched OFF due to lack of payment.
AD-HOC DEBITS AND CREDITS:
Both billing packages support ad-hoc account debits and credits which can be allocated to a customer’s account with detailed descriptions.
For example, if a technician is sent out to replace a broken LED DC light bulb this can be charged directly to the customer’s account and will only be due for payment at the billing package debit or expiry date.
Alternatively, a credit value may be issued if, for example, the system had to be switched OFF in order to fully recharge the battery after a very bad patch of weather.
Every transaction is logged with the user- administrators details in an advanced search-able audit trail.
Specialized Solar Systems are continuously researching and pioneering new methods to enhance and add value to products and better solutions. Currently, there are over 200 Solar Towers supplying low voltage DC for up to 3600 households for the first phase of an electrification project in Diepsloot, South Africa. The technology has performed satisfactorily and within the original design mandate. The take-up by the Diepsloot community has far exceeded expectations. There is a lot of commercial interest being shown due to the smart power delivery infrastructure and take-up.
FIBER INTERNET CONNECTIVITY
Fiber connectivity is currently being finalized for the Solar Tower distribution network. Each Solar Tower will be equipped and power low cost high-speed, low-latency fiber Internet connectivity. The Solar Tower will distribute the fiber-connectivity to contracted households each receiving monthly data. This could be included in the households bundled DC appliance package offerings.
HIGH VOLTAGE 350VDC
Specialized Solar Systems is spearheading a project in collaboration with the Netherlands universities from the Hague and Amsterdam and several South African Universities of Technology. The project aims to demonstrate 350VDC high voltage transfer of power between Solar Towers and allowing for grid-interconnectivity. This will ensure that Solar Towers become a permanent infrastructure giving customer more options with the possibility of cooking and operating high powered electrical devices.
SPECIALIZED SOLAR SYSTEMS – A proven track record of delivery
Using low voltage DC, many power boxes or stand-alone power storage systems were designed for specific and customized purposes. Devices that provide lighting, emergency systems assistance, and backup power, entertainment, and charging of cell phones.
Prototype Solar Home Systems (SHS) or DC Microgrids with efficient DC LED lighting and appliances were developed and deployed in rural locations Transkei, Limpopo and KwaZulu Natal and Malawi to test and gauge system performance and customer satisfaction.
Developed urban-modeled DC Micro-grids for rural and township roll-out. Consultation with electrical engineers on safety features for urban applications. The social impact study report was completed by Bianco Curry. Collaboration with the Stellenbosch Sustainability Institute and Innovation Lab (Stellenbosch University) and the University of the Free State were formed and community training models for the introduction to DC Microgrids were established. Documentation for rural low voltage electrification was developed. An online management system with remote switching begins.
Tsomo, KwaZulu Natal: 200 SHS’s, Botswana: 250 SHS’s, SHS’s retail outlets in Kenya, and Zambia were formed.
SHS electrification projects for indigent and disconnected communities. Ongoing product development and improvement resulting in scalable, modular, and remotely managed SHS with implementation and sustainable programs documented for NGO’s, government Department of Energy (DOE) Concessions. New billing methods, POS, and billing methods applied to in house software development. Department of Energy and concession holder implementation. Bill Gates foundation approved 1750 systems.
DoE, Matatiele District, Eastern Cape; 900 SHS’s. Botswana: 400 SHS’s for schools, post offices, and rural/urban households. North West municipality upgrade of informal settlement with 1850 units. DoE, Schmidtsdrift, Northern Cape 1850 SHS’s. Department Agriculture and land reform, Groblershoop Municipality Northern Cape 410 SHS’s. DoE Limpopo Concessionaire: 1500 SHS’s. DoE Oudtshoorn 660 SHS’s. LDM Engineering, Eastern Cape: 800 SHS’s. Power Mode, Eastern Cape 800. Peer Africa, ! Kheis, Northern Cape: 500 SHS’s. Defy 100 DC Fridge systems. 2016 – Private funding initiatives. Developments of larger mini- gridded System prototypes. Concessionaire, Polokwane, Limpopo: 700 SHS’s. Jabula, Western Cape, Substation Prototype 1 Substation 8 houses.
Improved SHS’s. Focus on Solar Tower development with collaboration with Victron Energy. Upgrade on web remote management systems to include advance remote system management, consumption metering, and API payment integrations.
DOE, Western Cape: 1000 SHS’s. DOE, Northern province: 573 SHS’s. DOE Oudtshoorn 200 SHS’s. Anglo Trust, Eastern Cape: 231 SHS’s. DCGO, Nkaneng 14 Substations/53 homes electrified. KEP, Transkei 200 SHS including refrigeration. DOE, Concessionaire, Polokwane, 1650 SHS.
2019 – 2020
Ongoing Solar Tower ITC Networked product development and expansion planning for the inclusion of high voltage 350VDC grid Solar Tower networks and fiber networks for the foreseeable future linking DC Microgrids with traditional AC grid allowing for bi-lateral transformation managed by smart electronics and ICT.
Diepsloot, 200 Solar Towers with ability to 3600 households. Limpopo DOE; 650 SHS.