This document summarizes Trama TecnoAmbiental's (TTA) experience developing off-grid rural electrification microgrid projects since 1987. It discusses TTA's project cycle and highlights key challenges including characterizing energy demand, developing an appropriate business model, and implementing innovative metering and tariff concepts to ensure technical and economic sustainability. Critical success factors include quality engineering solutions, effective procurement and logistics, and ongoing operations and maintenance. The document also reviews TTA's implementation of an "energy daily allowance" tariff and dispenser system in projects to manage individual energy use and demand.

1. Lecciones y factores de éxito -
Microrredes Rurales Fotovoltaicas
Unai Arrieta Salgado
Trama TecnoAmbiental (TTA), Barcelona
unai.arrieta@tta.com.es 1
Energía fuera de la red para el desarrollo rural en América
Latina y el Caribe - Taller de clausura
Ciudad de Panamá
2-3 Mayo 2017

2. • SME Founded in Barcelona en 1986
• Independent consultants and engineers in distributed renewable energy
 Since 1987: Off-grid rural electrification practitioners
 Design and Project management of RE-hybrid micro-power plants and micro grids for rural
electrification in southern Europe, Africa, Latin America, Oceania …
 Micro-grid project developers, implementers and operators
 Other areas: Energy Efficiency, Sustainable Building, Distributed Urban PV
Trama TecnoAmbiental (TTA)
Member of:

3. 3 villages
(Chad)
2002
2005
2009
Santo Antâo
(Cape Verde)
Las Balsas (Ecuador)
Akane
(Morocco)
2012
Cal Peraire
(Spain)
1987:
Beginning
Farmhouses PV
electrification
(Spain)
1994
2006
Escuain
(Spain)
1997
Font:TTA
2007
Atouf
(Palestine)
Diakha Madina (Senegal)
Beni Said
(Morocco)
Isla
Floreana
(Ecuador)
2015
2016
4 villages
(Ghana)
Burundi
La Rambla del Agua
(Spain)
Tanzania
Rwanda and
Kenya
PV off-grid Micro-grid Experience
2014
2013

4. PROJECT CYCLE OF A MICRO-GRID
1. Project identification 2. Need assessment and
data gathering
4. Techno-economic
analysis
5. Engineering 6. Procurement
7. Installation 8. Commissioning 9. Capacity building 10. Service operation
3. Business model and
tariff definition

5. Usos
productiv
os
CHALLENGE: SHARING THE ENERGY AVAILABLE WITHOUT CONFLICTS
 Need comprehensive experience in technical and management levels
with multidisciplinary skills
 Need innovative approach to energy distribution and metering!

6. HIGHLIGHTED CHALLENGES OF MICROGRIDS
Social Aspects
• Identifying final
users’ energy needs
(energy services-
electricity)
• Sharing the
available energy /
resource without
conflicts
Management of
individual energy
demand
• Provide incentives
to use the available
energy at moments
with generation
surplus
• Accumulate energy
not used, for each
user, independently
• Guide users on how
to improve energy
use habits
Technical-economic
sustainability of
service
• Ensure that battery,
inverters etc.
operate within
design thresholds
• Reduce tariff
collection
uncertainty
• Tariffs reflect real
operating costs

7. REGULATORY FRAMEWORK
BUSINESS MODEL
CRITICAL SUCCESS FACTORS
DEMAND
CHARACTERIZATION
QUALITY SOLUTION
(ENGINEERING &
COMPONENTS)
METERING
CONCEPT
and TARIFFS
PROCUREMENT &
LOGISTICS
O&M

8. REGULATORY FRAMEWORK
BUSINESS MODEL
CRITICAL SUCCESS FACTORS
DEMAND
CHARACTERIZATION
QUALITY SOLUTION
(ENGINEERING &
COMPONENTS)
METERING
CONCEPT
and TARIFFS
PROCUREMENT &
LOGISTICS
O&M

9. 1. ASSESS THE ENERGY DEMAND
Demand characterisation
2. COMPARATIVE DEMAND
CHARACTERISATION
Assessment of load categories
based on data analysis of similar
villages and own experience
– Through surveys, questionnaires and own observation
– The users are not experts
– Define users’ demand requirements
– Consider socio-economic data
Pefil consumo para uso doméstico, servicios, pequeña industria (<200
kWh/mes)
0%
5%
10%
15%
20%
25%
3,5
14
24,5
35
45,5
56
66,5
77
87,5
98
108,5
119
129,5
140
Rangos de consumo mensual (kWh)
usuarios%deltotal

12. Added value solution: Scalable
Monte Trigo, Cape Verde
Chad

13. Financial Sustainability :
• Tariffs designed to ensure enough revenues to cover its M&O&M, replacement and
unforeseen costs and, including or not, pay-back of investment
Tariff Schemes for energy management
Tariff schemes:
-Power-based
-Energy-based
-Service-based (EDA)
-Combination of above
Linked to the quality of service:
Service duration Service disruption
(max)
24/7 ˂ 1%
18/24, 12/24, … ˂ 10%, ˂ 15%, …
Weekends On demand
Seasonal …

14. METERING AND ENERGY MANAGEMENT
Electricity Dispenser

15. ENERGY DAILY ALLOWANCE TARIFF
IMPLEMENTATION
Electricity metering
Vending system
Energy and Financial
audit
Clients’ management and
financial statements
X Wh/day (flexible) and Y W or kW; pre-paid fixed monthly fee ($/month),
different for different energy/power levels. Dispensers allow for a flexible
and smart energy demand:
•Management of individual energy depending on status of micro-grid.
•User interface red/green LEDs for awareness and demand management
•Equipment operates within design thresholds extending life
•Simplified financial planning and transparent, between operator and users

16. The EDA algorithm
As an analogy, we can imagine the
dispenser as a buffer water tank
The tank gets a constant trickle inflow
from the micro-grid proportional to the
contracted energy daily allowance
The tank empties as energy is consumed
When the consumption is equal to the fill
up rate we are in balanced consumption
The tank has a capacity equivalent to 3
days of energy daily allowance
You can use this energy anytime but you
cannot store more units than the tank’s
capacity

17. DEMAND SIDE MANAGEMENT

18. DEMAND SIDE MANAGEMENT
Give incentives to the users to shift their demand to follow energy
production times
Radiation
W/m2
0
100
200
300
400
500
600
700
800
900
1000
Bonus
f > 52 Hz
Restriction
f < 49 Hz
Normal Normal
08:00 12:00 16:0006:00 18:00
Low SOC of
battery
Battery fully
charged

19. Legal Framework
• Create or adapt regulation to the reality of off-grid areas, both in
terms of socio-economic aspects and technology aspects
• Open to different tariff schemes (such as EDA) and allow
methodologies to set schemes/rates different to grid-connected (for
instance, rates based on agreements between users and operators)
• Set how/what subsidies are applicable; rather subsidise capital
costs than recurrent tariffs
• Regulate and recognise the “right to exist” (as any other business)
of private, local micro-grid operators
• Simplify administrative / bureaucratic processes for small projects
(for instance below 1MW, 2MW etc.)

20. Cost structure – capital costs
CAPEX
Generation
(Wp)
Storage
(kWh)
Conversion
(kVA)
Distribution
grid
(km,
connexions)
Logistics/Remoteness
Services/Localmarketmaturity/risk

22. MUCHAS
GRACIAS!
unai.arrieta@tta.com.es
www.tta.com.es