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Rural electrification: the potential and limitations of solar power
Last registered on December 20, 2016


Trial Information
General Information
Rural electrification: the potential and limitations of solar power
Initial registration date
December 22, 2015
Last updated
December 20, 2016 2:09 AM EST
Primary Investigator
Universit├Ąt Mannheim
Other Primary Investigator(s)
PI Affiliation
IIES, Stockholms Universitet
PI Affiliation
IIES, Stockholms Universitet
Additional Trial Information
On going
Start date
End date
Secondary IDs
This study is motivated by three observations. First, nearly a fifth of the world population lacks access to electricity. Second, it is estimated that 530 million people in, primarily rural, sub-Saharan Africa will remain off-grid for the next 30 years. Finally, due to slow expansion of national grids solar power is being promoted by many as a decentralized and clean solution requiring minimal infrastructure investments. Yet very little is known about the benefits and limitations of solar power at the household level.

The focus of this project is to provide the first experimental evidence on the adoption and impact of solar power at the household level. We will examine how price, liquidity constraints and information influence the decision to adopt a clean and renewable energy source such as solar power and how access to this source of energy influences household outcomes. In order to experimentally test how price and liquidity constraints influence take up of solar lamps we randomly allocate vouchers to households that offer a subsidy of 0, 25, 50 or 100% on solar lamps.

With our experimental design, we will be able to answer four research questions: 1) how does access to solar power influence outcomes of individuals and households? In particular, how does ownership of a lamp influence educational attainment of children? 2) how does demand for a solar powered light source vary with price? 3) are there spill over effects in adoption of a renewable energy source? 4) how do learning and experience influence adoption of a renewable and clean energy source?
External Link(s)
Registration Citation
Aevarsdottir, Anna, Nicholas Barton and Tessa Bold. 2016. "Rural electrification: the potential and limitations of solar power." AEA RCT Registry. December 20. https://doi.org/10.1257/rct.989-3.0.
Former Citation
Aevarsdottir, Anna et al. 2016. "Rural electrification: the potential and limitations of solar power." AEA RCT Registry. December 20. http://www.socialscienceregistry.org/trials/989/history/12674.
Experimental Details
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
Reading ability, household income, income generating activities, time use
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
We have designed a randomised field experiment in which households in rural Tanzania will be offered the chance to purchase solar powered lamps with solar panels. We randomly allocate vouchers to households that offer a subsidy on solar lamps.
Experimental Design Details
Randomization Method
Schools and individuals were selected by computer randomisation, subsidies were decided by public lottery.
Randomization Unit
Household level randomisation is implemented at the school level.
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
70 Schools
Sample size: planned number of observations
2100 households
Sample size (or number of clusters) by treatment arms
10 pure control schools, 60 schools with treatments (30 for each of the subsidy arms)
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
To determine the sample size for our experiment, we focus on three core outcome variables: 1) technology adoption (purchase of lamp) 2) educational achievement (test scores) and 3) female employment. Based on data provided by GiveWatts and test score data from the World Bank Service Delivery Initiative in Tanzania (Bold, Gauthier, Maestad, Svensson, 2011) and following a protocol requiring 80\% power of detecting a significant difference at the two-sided 10\% level, we find that sample of 1800 households would detect a 0.25 standard deviation increase in test scores and female employment and a 0.1 standard deviation increase in technology adoption with 80\% power. The sample is therefore set to 1800 households. For the administrative reasons set out above, we will conduct a stratified randomized controlled trial, by first randomly selecting 60 schools eligible for the GiveWatts programme, randomizing sets of subsidies between them and then randomly selecting 30 households within the school to be allocated -- again randomly -- a subsidy level for the solar lamp. Given that there is the possibility of lamp sharing and thus potential spill-over effects in outcomes we decided to add an additional 10 schools to our sample that would serve as pure control schools (without any lamp subsidies). From each of the pure control schools we sampled 30 households. Thus the final study sample consists of 2100 households.
IRB Name
Tanzania Commission for Science and Technology
IRB Approval Date
IRB Approval Number
IRB Name
Tanzania Commission for Science and Technology
IRB Approval Date
IRB Approval Number
Analysis Plan

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Study Withdrawal
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Data Publication
Data Publication
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Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)